GBT 1299-2014 Tool and Mould Steels [PDF]

Zitiervorschau

ICS 77.140.45 H 40

National Standard of the People's Republic of China GB/T 1299—2014 Replace GB/T 1299-2000, GB/T 1298-2008

Tool and Mould Steels 工模具钢 （English Translation） （征求意见稿）

Issued date: 2014-12-05

Implementation date：2019-09-01

Issued by General Administration of Quality Supervision, Inspection and Quarantine of the People's Republic of China Standardization Administration of the People's Republic

of

China

GB/T XXXX-XXXX

Contents Forwards ................................................................................. 3 1 Scope ................................................................................. 5 2 Normative references .................................................................. 5 3 Classification ........................................................................ 8 4 Ordering information .................................................................. 9 5 Dimensions,shapeand tolerances ........................................................ 9 5.1 Dimensions,shape and tolerances of hot rolled steel bars and wire rods .......... 9 5.2 Dimensions,shape and tolerances of forged bars ................................. 13 5.3 Dimensions, shape and tolerances of cold drawn steel bars ...................... 14 5.4 Dimensions, shape and tolerances of bright steel bars .......................... 15 5.5 Dimensions, shape and tolerances of machined bars .............................. 15 5.6 Weight ......................................................................... 15 6 Technical requirements ............................................................... 15 6.1 Steel grades and chemical composition .......................................... 15 6.2 Melting method ................................................................. 23 6.3 Delivery condition ............................................................. 23 6.4 Hardness ....................................................................... 23 6.5 Macrostructure ................................................................. 29 6.6 Microstructure ................................................................. 30 6.7 Non-metallic inclusions ........................................................ 32 6.8 Decarburization ................................................................ 33 6.9 Relative permeability .......................................................... 34 6.10 Ultrasonic testing ............................................................ 34 6.11 Surface quality ............................................................... 35 6.12 Special requirements .......................................................... 36 7 Test methods ......................................................................... 36 8 Inspection rules ..................................................................... 37 8.1 Inspection and acceptance ...................................................... 37 8.4 Retest and quality judgement rules ............................................. 38 9 Packaging, marking and certificate of quality ........................................ 38 Annex A ................................................................................. 40 Annex B ................................................................................. 52 Annex C ................................................................................. 56 Annex D ................................................................................. 66

2

GB/T XXXX-XXXX

Forwards XXX is in charge of this English translation. In case of any doubt about the contents of English translation, the Chinese original shall be considered authoritative. This standard is drafted in accordance with the rules given in the GB/T 1.1-2009. This standard replaces the GB/T 1299-2000 (Alloy Tool Steel) and the GB/T 1298-2008 (Carbon Tool Steel) in whole. The following changes have been made with respect to the GB/T 1299-2000: —— The title of the standard was revised to Tool and Mould Steels; —— The maximum diameter/side length of forged rounds/squares was expanded to 800mm; the maximum dimension of hot rolled flats was expanded to 200mm (thickness) ×

850mm

（ width ） ; the maximum dimension of forged flats was expanded to 1000mm (thickness) × 1500mm (width); —— Revised the requirements for the length at delivery and dimensional tolerances of hot rolled rounds and squares; —— Revised the requirements for dimensions, shape and tolerances of hot rolled flats; — — Revised the requirements for dimensions, shape and tolerances of forged rounds, squares and flats; — — Added the requirements for dimensions, shape and tolerances of hot rolled wire rods, bright bars and machined bars. —— Added the requirements for the weight at delivery. — — Added two steel types: unalloyed steels for cutting tools and moulds and steels for rollers. —— Added 55 steel grades aswell as the relevant technical requirements, including 8 unalloyed steels for cutting tools and moulds: T7, T8, T8Mn, T9, T10, T11, T12 and T13 (original included in GB/T 1298-2008);1 shock-resisting tool steel 6CrW2SiV; 5 steels for rollers: 9Cr2V, 9Cr2Mo, 9Cr2MoV, 8Cr3NiMoV, 9Cr5NiMoV; 8 cold-work tool steels: MnCrWV, 7CrMn2Mo, 5Cr8MoVSi, Cr8Mo2VSi, W6Mo5Cr4V2, Cr8, Cr12W, 7Cr7Mo2V2Si; 10 hot-work tool steels:4CrNi4Mo,

4Cr2NiMoV,

5CrNi2MoV,

5Cr2NiMoVSi,

4Cr5MoWVSi,

5Cr5WMoSi,4Cr5Mo2V,

3Cr3Mo3V, 4Cr5Mo3V, 3Cr3Mo3VCo3; 19 plastic mould steels:SM45, SM50, SM55, 4Cr2Mn1MoS, 8Cr2MnWMoVS,

5CrNiMnMoVSCa,

2CrNiMoMnV,

06Ni6CrMoVTiAl,

2CrNi3MoAl,

1Ni3MnCuMoAl,

00Ni18Co8Mo5TiAl, 2Cr13, 4Cr13, 4Cr13NiVSi, 2Cr17Ni2, 3Cr17Mo, 3Cr17NiMoV, 9Cr18, 9Cr18Mo; 4

special-purpose

tool

steels:

2Cr25Ni20Si2,

0Cr17Ni4Cu4Nb,

Ni25Cr15Ti2MoMn,

Ni53Cr19Mo3TiNb. 3

GB/T XXXX-XXXX —— Cancelled the requirements for permissible deviation for product analysis. —— Revised the requirements for phosphorus, sulfurand other trace elements. —— Revised the requirements for the delivery condition of steel products. ——

Revised the acceptable severity levels of macrostructure and added the test

methods for the macrostructure of electro slag remelted steels. —— Added the acceptable severity levels of eutectic carbides of round and square bars. —— Added the requirements for non-metallic inclusion inspection. —— Added the requirement for ultrasonic testing. —— Tightened the surface quality requirement for steel productsand added the surface quality requirements for bright bars and machined bars. — — Added “standard rating photographs for pearlite structure and carbide network” for unalloyed steels in Annex A (normative) (that is annex A in GB/T1298-2008); —— Revised the “Cross-references of Chinese tool steel designations to designations in other national systems”in original Annex B (informative) and changed it to Annex D (informative); — — Added Annex B (normative) “Test methods for determining hardenability of nonalloy tool steels” (that is Annex B in GB/T 1298-2008 and added the requirement that the sampling position shall be in accordance with GB/T 225). —— Added Annex C (Informative) “Main characteristics and applications of the steel grades”. This standard was proposed by China Iron and Steel Association. This standard was prepared by SAC/TC 183Technical Committee on Steel Standardization of China. The main drafting bodies of this standard: Dongbei Special Steel Group Fushun Special Steel Co., Ltd., China Iron and Steel Research Institute, China Metallurgical Information and Standard Institute. The participant drafting bodies of this standard: The main drafter of this standard: Kang Aijun, Ma Dangsen, Gu Qiang, Luan Yan, Chi Hongxiao, Liu Zhentian, Dong Xuedong, Dai Qiang. The participant drafter of this standard: Chu Yanli, Zhou Liandi, Xin Donghui, Miu Zhigang, Feng Chunyu. The previous editions of this standard are as follows: —— GB/T1299-1977, GB/T1299-1985, GB/T1299-2000; —— GB/T1298-1977, GB/T1298-1986, GB/T1298-2008. 4

GB/T XXXX-XXXX

Tool and die steels 1 Scope This

standard

specifies

the

requirements

for

classification,

order

information,

dimensions, shape, mass and tolerances, test methods, inspection rules, packaging, marking, and certificate of quality, as well as the technical requirements of tool and mould steels. This standard applies to tool and mould steels in the form of hot-rolled, forged, cold drawn, and bright bars, as well as to those products delivered in machined condition. The chemical composition in this standard also applies to ingot, billet and their products.

2 Normative references The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.

GB/T 223.5, Steel and iron – Determination of acid-soluble silicon and total silicon content – Reduced molybdosilicate spectrophotometric method GB/T 223.8, Methods for chemical analysis of iron, steel and alloy-The sodium fluoride separation-EDTA titration method for the determination of aluminium content GB/T 223.11, Iron, steel and alloy – Determination of chrome content – Visual titration or potentiometric titration method GB/T 223.13, Methods for chemical analysis of iron, steel and alloy – The ammonium ferrous sulfate titration method for the determination of vanadium content GB/T 223.14, Methods for chemical analysis of iron, steel and alloy – The N-benzoy-Nphenylhydroxylamine extraction photometric method for the determination of vanadium content GB/T 223.18, Methods for chemical analysis of iron, steel and alloy – The sodium thiosulfate separation iodimetric method for the determination of copper content GB/T 223.19, Methods for chemical analysis of iron, steel and alloy - The neocuproinechloroform extraction photometric method for the determination of copper content GB/T 223.22, Methods for chemical analysis of iron, steel and alloy- The nitroso-R-salt spectrophotometric method for the determination of cobalt content GB/T 223.23, Iron, steel and alloy – Determination of nickel content – The dimethylglyoxime spectrophotometric method GB/T 223.26, Steel and iron – Determination of molybdenum content – The thiocyanate spectrophotometric method 5

GB/T XXXX-XXXX

GB/T 223.26, Iron, steel and alloy – Determination of molybdenum content – The thiocyanate spectrophotometric method GB/T 223.28, Methods for chemical analysis of iron, steel and alloy – The ɑ benzoinoxime gravimetric method for the determination of molybdenum content GB/T 223.29, Iron, steel and alloy – Determination of lead content – Carrier precipitation – xylenol orange spectrophotometric method GB/T 223.31, Iron, steel and alloy – Determination of arsenic content – Distillation – molybdenum blue spectrophotometric method GB/T 223.43, Iron, steel and alloy – Determination of tungsten content – Gravimetric method and spectrophotometric method GB/T 223.47, Methods for chemical analysis of iron, steel and alloy – The carrier precipitation – molybdenum blue potometric method for the determination of antimony content GB/T 223.48, Methods for chemical analysis of iron, steel and alloy – The semixylenol orange photormetric method for the determination of bismuth content GB/T

223.50,

Methods for

chemical analysis

of iron,

steel and

alloy

–

The

phenylfluorone – CTMAB direct photometric method for the determination of tin content GB/T 223.53,Methods for chemical analysis of iron, steel and alloy – The flame atomic absorption spectrophotometric method for the determination of copper content GB/T 223.54,Methods for chemical analysis of iron, steel and alloy – The flame atomic absorption spectrophotometric method for the determination of nickel content GB/T 223.58, Methods for chemical analysis of iron, steel and alloy – The sodium arsenite-sodium nitrite titrimetric method for the determination of manganese content GB/T 223.59, Iron, steel and alloy – Determination of phosphorus content – Bismuth phosphomolybdate

spectrophotometric

method

and

antimony

phosphomolybdate

blue

spectrophotometric method GB/T 223.60, Methods for chemical analysis of iron, steel and alloy – The perchloric acid dehydration gravimetric method for the determination of silicon content GB/T 223.61, Methods for chemical analysis of iron, steel and alloy – The ammonium phosphomolybdate volumetric method for the determination of phosphorus content GB/T 223.62,Methods for chemical analysis of iron, steel and alloy – The Butyl Acetate Extraction Photometric Method for the Determination of Phosphorus Content GB/T 223.63, Methods for chemical analysis of iron, steel and alloy – The sodium (potassium) periodate photometric method for the determination of manganese content 6

GB/T XXXX-XXXX

GB/T 223.64, Iron, steel and alloy – Determination of manganese content – Flame atomic absorption spectrometric method GB/T 223.67, Iron, steel and alloy – Determination of sulfur content – Methylene blue spectrophotometric method GB/T 223.68, Methods for chemical analysis of iron, steel and alloy – The potassium iodate titration method after combustion in the pipe furnace for the determination of sulfur content GB/T 223.69, Iron, steel and alloy – Determination of carbon contents – Gasvolumetric method after combustion in the pipe furnace GB/T 223.71, Methods for chemical analysis of iron, steel and alloy – The gravimetric method after combustion in the pipe furnace for the determination of carbon content GB/T 223.72, Iron, steel and alloy – Determination of sulfur content – Gravimetric method GB/T 223.76, Methods for chemical analysis of iron, steel and alloy – The flame atomic absorption spectrometric method for the determination of vanadium content GB/T 223.82, Steel and iron – Determination of hydrogen content – Inert gas impulse fusion heat conductivity method GB/T 223.85, Iron, steel and alloy – Determination of sulfur content – Infrared absorption method after combustion in an induction furnace GB/T 223.86, Iron, steel and alloy – Determination of total carbon content – Infrared absorption method after combustion in an induction furnace GB/T 224, Determination of depth of decarburization of steels GB/T 225, Steel – Hardenability test by end quenching (Jominy test) GB/T 226, Etch test for macrostructure and defect of steels GB/T 230.1, Metallic Rockwell hardness test – Part 1: Test method ( scales A, B, C, D, E, F, G, H, K, N, T) GB/T 231.1, Metallic materials – Brinell hardness test – Part 1:Test method GB/T 702-2008, Hot-rolled steel bars – Dimensions, shape, weight and tolerances GB/T 905-1994 Dimension, shape, weight and tolerance for cold-drawn round, square and hexagonal steels GB/T 908, Forged steel bars – Dimensions, shape, weight and tolerances GB/T 1979, Standard diagrams for macrostructure and defect of structural steels GB/T 2101, General requirement of acceptance, packaging, marking and certificate for section steel 7

GB/T XXXX-XXXX

GB/T 3207 Bright steels GB/T 4336, Standard test method for spark discharge atomic emission spectrometric analysis of carbon and low-alloy steel (routine method) GB/T 6402-2008 Steel forgings – Method for ultrasonic testing GB/T 6394 Metal – methods for estimating the average grain size GB/T 10561, Steel – Determination of content of nonmetallic inclusions – Micrographic method using standards diagrams GB/T 11261, Steel and iron – Determination of oxygen content – The pulse heating inert gas fusion-infra-red absorption method GB/T 13298, Inspection method of microstructure for metals GB/T 14979-1994 Eutectic carbide of steel – Micrographic method using standard diagrams GB/T 14981 GB/T 17505, Steel and steel products – General technical delivery GB/T 20066, Steel and iron – Sampling and preparation of samples for the determination of chemical composition GB/T 20123, Steel and iron – Determination of total carbon and sulfur content – Infrared absorption method after combustion in an induction furnace (routine method) GB/T

20124,

Steel

and

iron

–

Determination

of

nitrogen

content

–

Thermal

conductimetric method after fusion in a current of inert gas (Routine method) GJB 937-1990 Measurement method for permeability of feebly magnetic materials ASTM A604 Standard test method for macroetch testing of consumable electrode remelted steel bars and billets

3 Classification 3.1 The steels are classified into 8 types according to their applications: a) unalloyed steels for cutting tools and moulds b) steels for measuring tools and cutting tools c) shock-resisting steels d) steels for rollers e) cold-work tool steels f) hot-work tool steels g) plastic mould steels h) special-purpose tool steels 8

GB/T XXXX-XXXX

3.2 The steels are classified into 2 types according to their working method after delivery: a) steels used for pressure work (UP): 1) used for hot pressure work (UHP); 2) used for cold pressure work (UCP). b) steels used for cut work (UC). The working method of the steel products after delivery shall be noted in the contract.

3.3 The steels are classified into 4 types according to their chemical composition: a) unalloyed tool steels (the designation of the steel grades begins with “T”) b) alloyed tool steels c) unalloyed mould steels (the designation of the steel grades begins with “SM”) d) alloyed mould steels Note: The unalloyed tool steels are originally known as carbon tool steels.

4 Ordering information Orders or contracts for steel products under this standard shall include but not limited to the following information: a) The reference to this standard; b) The designation of the product form; c) Steel grades; d) Melting method (see section 6.2); e) Delivery condition; f) Dimensions and tolerance groups (see section 5); g) The working method after delivery (see section 3.2) h) Other special requirements (see section 6.12)

5 Dimensions,shapeand tolerances

5.1

Dimensions,shape and tolerances of hot rolled steel bars and wire rods

5.1.1 Hot rolled rounds and squares 5.1.1.1

For hot rolled rounds and squares, the dimensions, shape and tolerances shall

comply with GB/T 702-2008, class 2. Any other tolerance class required by the purchaser shall be noted in the contract. 9

GB/T XXXX-XXXX 5.1.1.2

The hot rolled rounds and squares are commonly delivered in the length of 2000mm

to 7000mm, and some short lengths not shorter than 1000mm are permissible if the weight of the short lengths takes up no more than 10% of total weight at delivery. When ordered as fixed lengths or multiple lengths, the length requirement shall be noted in the contract and the tolerances on length shall be +60/-0mm. 5.1.2 Hot rolled flats 5.1.2.1 dimensions and tolerances 5.1.2.1.1

For hot rolled flats whose nominal width is 10mm to 310mm (including), the

dimensions and tolerances shall conform to the requirement of table 1. 5.1.2.1.2

For hot rolled flats whose nominal width is above 310mm and up to 850mm, the

dimensions and tolerances shall conform to the requirement of table 2, and the tolerance class adopted shall be noted in the contract.

Table 1 Dimensions and tolerances for hot rolled flats whose nominal width is 10mm to 310mm (including) Nominal width 10 ＞10～18 ＞18～30 ＞30～50 ＞50～80 ＞80～160 ＞160～200 ＞200～250 ＞250～310

Tolerances, not bigger than ＋0.70 ＋0.80 ＋1.20 ＋1.60 ＋2.30 ＋2.50 ＋2.80 ＋3.00 ＋3.20

Nominal thickness ≥4～6 ＞6～10 ＞10～14 ＞14～25 ＞25～30 ＞30～60 ＞60～100 — —

in millimeter Tolerances, not bigger than ＋0.40 ＋0.50 ＋0.60 ＋0.80 ＋1.20 ＋1.40 ＋1.60 — —

Table 2 Dimensions and tolerances for hot rolled flats whose nominal width is above 310mm and up to 850mm

Nominal thickness

6～12 ＞12～20 ＞20～70

Dimensional Class 1 Nominal width＞300～ Nominal width ＞455～ 455 850 Tolerances Tolerances Tolerances Tolerances on the on the on the on the thickness width thickness width +1.2 +5.0 +1.5 +7.0 0 0 0 0 +1.2 +6.0 +1.5 +7.0 0 -2.0 0 -3.0 +1.4 +6.0 +1.7 +7.0 0 -2.0 0 -3.0

tolerances Class 2 Nominal width ＞300～ 850 Tolerances Tolerances on the on the thickness width +1.5 0 +1.6 +15.0 0 0 +1.8 0

in millimeter Class3 Nominal width＞300～ 455 Tolerances Tolerances on the on the thickness width

As negotiated

As negotiated

10

GB/T XXXX-XXXX ＞70～90 ＞90～100 ＞100～ 200

+2.0 0

+7.0 -3.0

+2.0 0

+10.0 -3.0

+3.0 0

+6.0 0

+15.0 0

5.1.2.2 Length at delivery 5.1.2.2.1

The length at delivery for hot rolled flats shall conform to the requirement of

table 3.

Table 3

General delivery length for hot rolled flats

Nominal width

General delivery length

The length of short-length bars

10～310

2 000～6 000

≥1 000

＞310～850

1 000～6 000

≥500

5.1.2.2.2

in millimeter

Weight percentage of short lengths at delivery the weight of the short lengths shall not take up more than 10% of total weight at delivery

When ordered as fixed lengths or multiple lengths, the length requirement shall

be noted in the contract and the tolerances on length shall be +60/-0mm. 5.1.2.3 Shape 5.1.2.3.1

The straightness of hot rolled flats shall conform to the requirement of table 4.

Table 4 Straightness of hot rolled flats Nominal width 10～310 ＞310～850

5.1.2.3.2

Dimensional toleranceclass — Class1 Class2, class3

in millimeter

Straightness (on wide surface and narrow surface) In any one-meter length Over total length No more than 4.0 0.40% of total length 3.0 0.30% of total length 4.0 0.40% of total length

The out-of-section of hot rolled flats are given in GB/T 702-2008, figure 4, and

the maximum tolerance for out-of-section (C value) shall meet the following requirements: a) For hot rolled flats whose nominal width is 10mm ～ 310mm (including), the C value shall be meet the requirement of table 12 in GB/T 702-2008; b) For hot rolled flats whose nominal width is above 310mmand up to 850mm, the C value shall meet the requirement of table 5 in this standard; c) Bigger C values out of specification can be removed by machining. The inspection of C values can be omitted if it can be guaranteed by the supplier. 11

GB/T XXXX-XXXX

Table 5 Permissible out-of-section (C values) for hot rolled flats whose width is above 310mm and up to 850mm Class 1 Nominal width Nominal width ＞310～455 ＞455～850 No more than 2.5 3.0 2.0 2.5 1.5 2.0 2.0 2.5

Nominal thickness 6～40 ＞40～70 ＞70～90 ＞90～200

in millimeter

Class 2 Nominal width Nominal ＞310～850 thickness No more than 6～13 8.0 ＞13～50 3.0 ＞50～200

Class 3 Nominal width Nominal ＞510～850 thickness No more than

100～200

10.0

8.0

5.1.2.3.3 The round corner radius R of hot rolled flats shall be in accordance with the requirement of table 6.

Table 6 Round corner radius of hot rolled flats Nominal width 10～310

Tolerance class — Class1 Class2, Class3

＞310～850

5.1.2.3.4

in millimeter

Round corner radius R，no more than slight blunt angle is permissible 4.0 10.0

The ends of hot rolled flats shall be cut straightly. The burrs on each end

shall be removed but burrs not longer than 5mm are permissible. Local deformation on the ends is permissible if the ends of hot rolled flats are cut with pressure shear. The cutting obliquity shall be in accordance with the requirement of table 7.

Table 7 Cutting obliquity of hot rolled flats Cutting obliquity

Nominal width 10～310 ＞310～850

5.1.2.3.5

in millimeter

Width ≤100 Width ＞100 thickness width

≤6.0 ≤8.0 ≤ 8% of the thickness ≤ 4% of the width

Hot rolled flats shall be free from evident twist. The length difference of the

two diagonal lines, measured on the same cross section shall be less than or equal to the tolerance of nominal width. 5.1.3

Hot rolled wire rods

The dimensions, shape and tolerances of hot rolled wire rods shall comply with the requirement of GB/T 14981.

12

GB/T XXXX-XXXX 5.2

Dimensions, shape and tolerances of forged bars

5.2.1

Forged rounds and squares

5.2.1.1

For forged rounds and squares whose nominal diameter or side length is 90-400mm

(including), the dimensions and tolerances shall comply with the requirements of class 2in table 3 in GB/T 908-2008. Any other tolerance class required by the purchaser shall be noted in the contract. 5.2.1.2 For forged rounds and squares whose nominal diameter or side length is above 400mm and up to 800mm, the dimensional tolerances shall comply with the requirements specified in table 8.

Table 8 Dimensional tolerances of forged rounds and squares whose nominal diameter or side length is above 400mm and up to 800mm Nominal diameter or side length ＞400～500 ＞500～800

5.2.1.3

in millimeter

Dimensional tolerances +12.0 -3.0 +13.0 -3.0

The forged rounds and squares are delivered in the length of no less than 1000mm,

and some short lengths not shorter than 500mm are permissible if the weight of the short lengths takes up no more than 10% of total weight at delivery. When ordered as fixed lengths or multiple lengths, the length requirement shall be noted in the contract and the tolerances on length shall be +80/-0mm. 5.2.1.4

For forged rounds, the straightness in any one-meter length shall be no bigger

than 5.0mm, and the straightness over the total length shall be no bigger than 0.50% of total length. The out of roundness of round bars shall be less than or equal to 70% of the tolerance of nominal diameter. 5.2.1.5

For forged squares, the straightness in any one-meter length shall be no bigger

than 5.0mm, and the straightness over the total length shall be no bigger than 0.50% of total length. The length difference of the two diagonal lines, measured on the same cross section shall be less than or equal to 70% of the tolerance of nominal side length;

For

squares whose side length is less than or equal to 300mm, the round corner radius R shall be no more than 5.0mm, and for squares whose side length is bigger than 300mm, the round corner radius R shall be no more than 10.0mm, while the distance between the two opposite 13

GB/T XXXX-XXXX round corners (diagonal line) shall be no less than 1.3 times of the nominal side length; It is not permissible to have evident twist for squares. 5.2.1.6 Both ends of forged rounds and squares shall be cut straightly by saw. 5.2.2 Forged flats 5.2.2.1

For forged flats whose nominal width is 40-300mm(including), the dimensions and

tolerances shall comply with the requirements of class 2 in table 4 in GB/T 908-2008. Any other tolerance class required by the purchaser shall be noted in the contract. 5.2.2.2

For forged flats whose nominal width is above 300mm and up to 1500mm, the

dimensions and tolerances shall comply with the requirements specified in table 9.

Table 9 Dimensions and tolerances of forged flats whose nominal width is above 300mm and up to 1500mm

in millimeter

Nominal thickness

Thickness tolerances Nominal width Width tolerances +8.0 +15.0 ＞160～200 ＞300～400 0 0 +10.0 +20.0 ＞200～400 ＞400～600 0 0 +15.0 +25.0 ＞400～1 000 ＞600～1500 0 0 2 The sectional area of forged flats is ≤ 1 200 000mm , and the ratio between width and thickness is ≤ 6:1.

5.2.2.3

The forged flats shall be delivered in the length of no less than 1000mm, and some

short lengths not shorter than 500mm are permissible if the weight of the short lengths takes up no more than 10% of total weight at delivery. When ordered as fixed lengths or multiple lengths, the length requirement shall be noted in the contract and the tolerances on length shall be +80/-0mm. 5.2.2.4

For forged flats, the straightness in any one-meter length shall be no bigger than

5.0mm, and the straightness over the total length shall be no bigger than 0.50% of total length. 5.2.2.5

For flats whose thickness or width is up to 300mm, the round corner radius R shall

be no more than 5.0mm, and for flats whose thickness or width is bigger than 300mm, the round corner radius R shall be no more than 10.0mm, while the length difference between the two diagonal lines, measured on the same cross section shall be less than or equal to the nominal width tolerance; It is not permissible to have evident twist for the flats. 5.2.2.6 Both ends of the forged flats shall be cut straightly by saw.

5.3

Dimensions, shape and tolerances of cold drawn steel bars 14

GB/T XXXX-XXXX The dimensions, shape and tolerances of cold drawn steel bars shall conform to class h11 requirement in GB/T905-1994. Any other tolerance class required by the purchaser shall be noted in the contract.

5.4

Dimensions, shape and tolerances of bright steel bars The dimensions, shape and tolerances of bright steel bars shall conform to class h11

requirement in GB/T3207-2008. Any other tolerance class required by the purchaser shall be noted in the contract. 5.5 Dimensions, shape and tolerances of machined bars 5.5.1

The dimensions, shape and tolerances of machined bars shall be in accordance with

the requirement of table 10. Any other tolerance requirement by the purchaser shall be noted in the contract.

Table 10 Dimensional tolerances of machined bars Nominal dimensions (diameter, side length or width and thickness) ≤200 ＞200～400 ＞400

5.5.2

in millimeter

Tolerances +1.5 0 +2.0 0 +3.0 0

The straightness of machined steel bars in any one-meter length shall be less than

or equal to 2.5mm, and the round corner radius R of squares and flats shall be less than or equal to 2.0mm. Any other requirements shall be in accordance with related standards.

5.6

Weight The steels are normally delivered in actual weight.

6 Technical requirements 6.1

Steel grades and chemical composition

6.1.1 The steel grades and chemical composition (product analysis) shall conform to the requirement in table 11 to 18.

15

GB/T XXXX-XXXX

Table 11 Grades and chemical composition of unalloyed steels for cutting tools and moulds Chemical composition（mass percentage）/% C Si 1-1 TOO070 T7 0.65～0.74 ≤0.35 1-2 TOO080 T8 0.75～0.84 ≤0.35 1-3 T01080 T8Mn 0.80～0.90 ≤0.35 1-4 TOO090 T9 0.85～0.94 ≤0.35 1-5 TOO100 T10 0.95～1.04 ≤0.35 1-6 TOO110 T11 1.05～1.14 ≤0.35 1-7 TOO120 T12 1.15～1.24 ≤0.35 1-8 TOO130 T13 1.25～1.35 ≤0.35 The steel grades in the table can be delivered in advanced quality, and “A” shall be added to the end of the grade. S.N.

Uni-code

Grades

Mn ≤0.40 ≤0.40 0.40～0.60 ≤0.40 ≤0.40 ≤0.40 ≤0.40 ≤0.40

Table 12 Grades and chemical composition of steels for measuring tools and cutting tools S.N.

Uni-code

Grades

2-1 2-2 2-3 2-4 2-5 2-6

T30219 T30108 T30200 T31200 T31209 T30800

9SiCr 8MnSi Cr06 Cr2 9Cr2 W

C 0.85～0.95 0.75～0.85 1.30～1.45 0.95～1.10 0.80～0.95 1.05～1.25

Chemical composition（mass percentage）/% Si Mn Cr 1.20～1.60 0.30～0.60 0.95～1.25 0.30～0.60 0.80～1.10 — ≤0.40 ≤0.40 0.50～0.70 ≤0.40 ≤0.40 1.30～1.65 ≤0.40 ≤0.40 1.30～1.70 ≤0.40 ≤0.40 0.10～0.30

W — — — — — 0.80～1.20

16

GB/T XXXX-XXXX

Table 13 Grades and chemical composition of shock-resisting steels S.N.

Uni-code

Grades

3-1 3-2 3-3 3-4 3-5 3-6

T40294 T40295 T40296 T40356 T40355 T40376

4CrW2Si 5CrW2Si 6CrW2Si 6CrMnSi2Mo1V 5Cr3MnSiMo1 6CrW2SiV

C 0.35～0.45 0.45～0.55 0.55～0.65 0.50～0.65 0.45～0.55 0.55～0.65

Si 0.80～1.10 0.50～0.80 0.50～0.80 1.75～2.25 0.20～1.00 0.70～1.00

Chemical composition（mass percentage）/% Mn Cr W ≤0.40 1.00～1.30 2.00～2.50 ≤0.40 1.00～1.30 2.00～2.50 ≤0.40 1.10～1.30 2.20～2.70 0.60～1.00 0.10～0.50 — 0.20～0.90 3.00～3.50 — 0.15～0.45 0.90～1.20 1.70～2.20

Mo — — — 0.20～1.35 1.30～1.80 —

V — — — 0.15～0.35 ≤0.35 0.10～0.20

Table 14 Grades and chemical composition of steels for rollers S.N.

a

Uni-code

4-1 T42239 4-2 T42309 4-3 T42319 4-4 T42518 4-5 T42519 Refer to table 19.

Grades 9Cr2V 9Cr2Mo 9Cr2MoV 8Cr3NiMoV 9Cr5NiMoV

C 0.85～0.95 0.85～0.95 0.80～0.90 0.82～0.90 0.82～0.90

Si 0.20～0.40 0.25～0.45 0.15～0.40 0.30～0.50 0.50～0.80

Mn 0.20～0.45 0.20～0.35 0.25～0.55 0.20～0.45 0.20～0.50

Chemical composition（mass percentage）/% P S Cr W a a 1.40～1.70 — a a 1.70～2.10 — a a 1.80～2.40 — ≤0.020 ≤0.015 2.80～3.20 — ≤0.020 ≤0.015 4.80～5.20 —

Mo Ni V — — 0.10～0.25 0.20～0.40 — — 0.20～0.40 — 0.05～0.15 0.20～0.40 0.60～0.80 0.05～0.15 0.20～0.40 0.30～0.50 0.10～0.20

17

GB/T XXXX-XXXX

Table 15 Grades and chemical composition of cold-work tool steels S.N.

Uni-code

5-1 5-2 5-3 5-4 5-5 5-6 5-7 5-8 5-9 5-10 5-11 5-12 5-13 5-14 5-15 5-16 5-17 5-18 5-19 a Refer

T20019 T20299 T21290 T20250 T21347 T21355 T21357 T21350 T21320 T21386 T21836 T21830 T21209 T21200 T21290 T21317 T21318 T21319 T21310 to table

Grades 9Mn2V 9CrWMn CrWMn MnCrWV 7CrMn2Mo 5Cr8MoVSi 7CrSiMnMoV Cr8Mo2SiV Cr4W2MoV 6Cr4W3Mo2VNb 6W6Mo5Cr4V W6Mo5Cr4V2 Cr8 Cr12 Cr12W 7Cr7Mo2V2Si Cr5Mo1V Cr12MoV Cr12Mo1V1 19.

C 0.85～0.95 0.85～0.95 0.90～1.05 0.90～1.05 0.65～0.75 0.48～0.53 0.65～0.75 0.95～1.03 1.12～1.25 0.60～0.70 0.55～0.65 0.80～0.90 1.60～1.90 2.00～2.30 2.00～2.30 0.68～0.78 0.95～1.05 1.45～1.70 1.40～1.60

Si ≤0.40 ≤0.40 ≤0.40 0.10～0.40 0.10～0.50 0.75～1.05 0.85～1.15 0.80～1.20 0.40～0.70 ≤0.40 ≤0.40 0.15～0.40 0.20～0.60 ≤0.40 0.10～0.40 0.70～1.20 ≤0.50 ≤0.40 ≤0.60

Mn 1.70～2.00 0.90～1.20 0.80～1.10 1.05～1.35 1.80～2.50 0.35～0.50 0.65～1.05 0.20～0.50 ≤0.40 ≤0.40 ≤0.60 0.20～0.45 0.20～0.60 ≤0.40 0.30～0.60 ≤0.40 ≤1.00 ≤0.40 ≤0.60

Chemical composition（mass S Cr a a — a a 0.50～0.80 a a 0.90～1.20 a a 0.50～0.70 a a 0.90～1.20 ≤0.030 ≤0.015 8.00～9.00 a a 0.90～1.20 a a 7.80～8.30 a a 3.50～4.00 a a 3.80～4.40 a a 3.70～4.30 a a 3.80～4.40 a a 7.50～8.50 a a 11.50～13.00 a a 11.00～13.00 a a 6.50～7.50 a a 4.75～5.50 a a 11.00～12.50 a a 11.00～13.00 P

percentage）/% W Mo — — 0.50～0.80 — 1.20～1.60 — 0.50～0.70 — — 0.90～1.40 — 1.25～1.70 — 0.20～0.50 — 2.00～2.80 1.90～2.60 0.80～1.20 2.50～3.50 1.80～2.50 6.00～7.00 4.50～5.50 5.50～6.75 4.50～5.50 — — — — 0.60～0.80 — — 1.90～2.30 — 0.90～1.40 — 0.40～0.60 — 0.70～1.20

V 0.10～0.25 — — 0.05～0.15 — 0.30～0.55 0.15～0.30 0.25～0.40 0.80～1.10 0.80～1.20 0.70～1.10 1.75～2.20 — — — 1.80～2.20 0.15～0.50 0.15～0.30 0.50～1.10

Nb — — — — — — — — — 0.20～0.35 — — — — — — — — —

Co — — — — — — — — — — — — — — — — — — ≤1.00

18

GB/T XXXX-XXXX

Table 16 Grades and chemical composition of hot-work tool steels S.N.

Unicode

Grades

6-1

T22345

5CrMnMo

6-2

T22505

5CrNiMo

6-3

T23504

4CrNi4Mo

6-4

T23514

4Cr2NiMoV

6-5

T23515

5CrNi2MoV

6-6

T23535

5Cr2NiMoVSi

6-7

T23208

8Cr3

6-8

T23274

4Cr5W2VSi

6-9

T23273

3Cr2W8V

6-10

T23352

4Cr5MoSiV

6-11

T23353

4Cr5MoSiV1

6-12

T23354

4Cr3Mo3SiV

6-13

T23355

5Cr4Mo3SiMnVA1

6-14

T23364

4CrMnSiMoV

6-15

T23375

5Cr5WMoSi

b

C 0.50～ 0.60 0.50～ 0.60 0.40～ 0.50 0.35～ 0.45 0.50～ 0.60 0.46～ 0.54 0.75～ 0.85 0.32～ 0.42 0.30～ 0.40 0.33～ 0.43 0.32～ 0.45 0.35～ 0.45 0.47～ 0.57 0.35～ 0.45 0.50～ 0.60

Si 0.25～ 0.60

P

0.10～ 0.40

Mn 1.20～ 1.60 0.50～ 0.80 0.20～ 0.50

≤0.40

≤0.40

a

0.10～ 0.40 0.60～ 0.90

0.60～ 0.90 0.40～ 0.60

≤0.40

≤0.40

a

0.80～ 1.20

≤0.40

a

≤0.40

≤0.40

a

0.80～ 1.20 0.80～ 1.20 0.80～ 1.20 0.80～ 1.10 0.80～ 1.10 0.75～ 1.10

0.20～ 0.50 0.20～ 0.50 0.25～ 0.70 0.80～ 1.10 0.80～ 1.10 0.20～ 0.50

≤0.40

a

a

a

a

a

a

a

a

a

a

a

Chemical composition（mass percentage）/% S Cr W Mo 0.60～ 0.15～ a — 0.90 0.30 0.50～ 0.15～ a — 0.80 0.30 1.20～ 0.15～ a — 1.50 0.35 1.80～ 0.45～ a — 2.20 0.60 0.80～ 0.35～ a — 1.20 0.55 1.50～ 0.80～ a — 2.00 1.20 3.20～ a — — 3.80 4.50～ 1.60～ a — 5.50 2.40 2.20～ 7.50～ a — 2.70 9.00 4.75～ 1.10～ a — 5.50 1.60 4.75～ 1.10～ a — 5.50 1.75 3.00～ 2.00～ a — 3.75 3.00 3.80～ 2.80～ a — 4.30 3.40 1.30～ 0.40～ a — 1.50 0.60 4.75～ 1.00～ 1.15～ a 5.50 1.50 1.65

Ni

V

Al

Co

—

—

—

—

—

—

—

—

—

—

—

—

—

—

—

—

—

—

—

—

—

—

—

—

—

—

—

—

0.30～ 0.70

—

—

—

—

—

1.40～ 1.80 3.80～ 4.30 1.10～ 1.50 1.50～ 1.80 0.80～ 1.20

0.10～ 0.30 0.05～ 0.15 0.30～ 0.50

—

—

— — — — — — — —

0.60～ 1.00 0.20～ 0.50 0.30～ 0.60 0.80～ 1.20 0.25～ 0.75 0.80～ 1.20 0.20～ 0.40 —

19

GB/T XXXX-XXXX

6-16

T23324

4Cr5MoWVSi

6-17

T23323

3Cr3Mo3W2V

6-18

T23325

5Cr4W5Mo2V

6-19

T23314

4Cr5Mo2V

6-20

T23313

3Cr3Mo3V

6-21

T23314

4Cr5Mo3V

6-22

T23393

3Cr3Mo3VCo3

0.32～ 0.40 0.32～ 0.42

0.80～ 1.20 0.60～ 0.90

0.20～ 0.50

0.40～ 0.50 0.35～ 0.42 0.28～ 0.35 0.35～ 0.40 0.28～ 0.35

a

a

≤0.65

a

a

≤0.40

≤0.40

a

a

0.25～ 0.50 0.10～ 0.40 0.30～ 0.50 0.10～ 0.40

0.40～ 0.60 0.15～ 0.45 0.30～ 0.50 0.15～ 0.45

≤0.020 ≤0.008 ≤0.030 ≤0.020 ≤0.030 ≤0.020 ≤0.030 ≤0.020

4.75～ 5.50 2.80～ 3.30

1.10～ 1.60 1.20～ 1.80

1.25～ 1.60 2.50～ 3.00

3.40～ 4.40

4.50～ 5.30

1.50～ 2.10

5.00～ 5.50 2.70～ 3.20 4.80～ 5.20 2.70～ 3.20

2.30～ 2.60 2.50～ 3.00 2.70～ 3.20 2.60～ 3.00

— — — —

— — — — — — —

0.20～ 0.50 0.80～ 1.20

—

0.70～ 1.10 0.60～ 0.80 0.40～ 0.70 0.40～ 0.60 0.40～ 0.70

—

—

—

—

—

—

—

—

—

—

—

2.50～ 3.00

a

Refer to table 19. Vanadium less than 0.20% is permissible if agreed upon between purchaser and supplier.

b

Table 17 Grades and chemical composition of plastic mould steels S.N.

Unicode

Grades

7-1

T10450

SM45

7-2

T10500

SM50

7-3

T10550

SM55

7-4

T25303

3Cr2Mo

7-5

T25553

3Cr2MnNiMo

7-6

T25344

4Cr2Mn1MoS

C 0.42～ 0.48 0.47～ 0.53 0.52～ 0.58 0.28～ 0.40 0.32～ 0.40 0.35～ 0.45

Si 0.17～ 0.37 0.17～ 0.37 0.17～ 0.37 0.20～ 0.80 0.20～ 0.40 0.30～ 0.50

Mn 0.50～ 0.80 0.50～ 0.80 0.50～ 0.80 0.60～ 1.00 1.10～ 1.50 1.40～ 1.60

Chemical composition（mass percentage）/% Cr W Mo Ni

P

S

a

a

—

—

—

a

a

—

—

a

a

—

—

a

a

a

a

≤0.030

0.05～ 0.10

1.40～ 2.00 1.70～ 2.00 1.80～ 2.00

— — —

V

Al

Co

其他

—

—

—

—

—

—

—

—

—

—

—

—

—

—

—

—

—

—

—

—

—

—

0.85～ 1.15

—

—

—

—

—

—

—

—

—

0.30～ 0.55 0.25～ 0.40 0.15～ 0.25

20

GB/T XXXX-XXXX

7-7

T25378

8Cr2MnWMoVS

7-8

T25515

5CrNiMnMoVSCa

7-9

T25512

2CrNiMoMnV

7-10 T25572

2CrNi3MoAl

7-11 T25611

1Ni3MnCuMoAl

7-12 A64060

06Ni6CrMoVTiAl

7-13 A64000 00Ni18Co8Mo5TiAl 7-14 S42023

2Cr13

7-15 S42043

4Cr13

7-16 T25444

4Cr13NiVSi

7-17 T25402

2Cr17Ni2

7-18 T25303

3Cr17Mo

7-19 T25513

3Cr17NiMoV

7-20 S44093

9Cr18

7-21 S46993

9Cr18MoV

a

0.75～ 0.85 0.50～ 0.60 0.24～ 0.30 0.20～ 0.30 0.10～ 0.20

≤0.40 ≤0.45 ≤0.30 0.20～ 0.50 ≤0.45

1.30～ 1.70 0.80～ 1.20 1.40～ 1.60 0.50～ 0.80 1.40～ 2.00

≤0.030 ≤0.030

0.08～ 0.15 0.06～ 0.15

2.30～ 2.60 0.80～ 1.20 1.25～ 1.45 1.20～ 1.80

0.70～ 1.10

0.50～ 0.80 0.30～ 0.60 0.45～ 0.60 0.20～ 0.40 0.20～ 0.50 0.90～ 1.20 4.50～ 5.00

0.80～ 1.20 0.80～ 1.20 3.00～ 4.00 2.90～ 3.40 5.50～ 6.50 17.5～ 18.5

—

—

≤0.60

—

—

—

—

—

—

—

≤0.025

≤0.015

—

a

a

≤0.030

≤0.015

—

—

—

≤0.06

≤0.50

≤0.50

a

a

1.30～ 1.60

—

≤0.03

≤0.10

≤0.15

≤0.010

≤0.010

≤0.60

—

≤1.00

≤1.00

a

a

≤0.60

≤0.80

a

a

0.90～ 1.20

0.40～ 0.70

≤0.010

≤0.003

≤1.00

≤1.50

a

a

≤1.00

≤1.50

a

a

0.30～ 0.60

0.60～ 0.80

≤0.025

≤0.005

≤0.80

≤0.80

a

a

≤0.80

≤0.80

a

a

0.16～ 0.25 0.36～ 0.45 0.36～ 0.45 0.12～ 0.22 0.33～ 0.45 0.32～ 0.40 0.90～ 1.00 0.85～ 0.95

12.00～ 14.00 12.00～ 14.00 13.00～ 14.00 15.00～ 17.00 15.50～ 17.50 16.00～ 18.00 17.00～ 19.00 17.00～ 19.00

— —

0.80～ 1.30 1.00～ 1.30

—

0.10～ 0.25 0.15～ 0.30 0.10～ 0.20

—

—

—

—

—

Ca:0.002～ 0.008

—

—

—

—

—

1.00～ 1.60 0.70～ 1.20 0.50～ 0.90 0.05～ 0.15

8.50～ 10.0

Cu:0.80～ 1.20 Ti:0.90～ 1.30 Ti:0.80～ 1.10

—

—

—

—

≤0.60

—

—

—

—

0.15～ 0.30 1.50～ 2.50

0.25～ 0.35

—

—

—

—

—

—

—

≤1.00

—

—

—

—

0.60～ 1.00

0.15～ 0.35

—

—

—

— — 0.08～ 0.16 —

— —

—

—

≤0.60

—

—

—

—

—

1.00～ 1.30

≤0.60

0.07～ 0.12

—

—

—

Refer to table 19.

21

GB/T XXXX-XXXX

Table 18 Grades and chemical composition of special-purpose tool steels S.N.

Unicode

Grades

C 0.65～ 0.75

Si

P

S

a

a

8-1

T26377 7Mn15Cr2Al3V2WMo

8-2

S31049

2Cr25Ni20Si2

≤0.25

1.50～ 2.50

≤1.50

a

a

8-3

S51740

0Cr17Ni4Cu4Nb

≤0.07

≤1.00

≤1.00

a

a

8-4

H21231

Ni25Cr15Ti2MoMn

≤0.08

≤0.80

Mn 14.50～ 16.50

≤1.00

≤2.00

Chemical composition（mass percentage）/% Cr W Mo Ni V 2.00～ 0.50～ 0.50～ 1.50～ — 2.50 0.80 0.80 2.00 24.00～ 18.00～ — — — 27.00 21.00 15.00～ 17.00

≤0.030 ≤0.020

13.50～ 17.00

≤0.015 ≤0.015

17.00～ 21.00

Al 2.30～ 3.30

Nb

Co

其他

—

—

—

—

—

—

—

—

Nb: 0.15～ 0.45

—

Cu:3.00～ 5.00

—

—

3.00～ 5.00

—

—

1.00～ 1.50

22.00～ 26.00

0.10～ 0.50

≤0.40

—

—

2.80～ 3.30

50.00～ 55.00

—

0.20～ 0.80

Nb+Ta : 4.75～ 5.50

— b

8-5

H07718

Ni53Cr19Mo3TiNb

≤0.08

≤0.35

≤0.35

≤ 1.00

Ti:1.80～ 2.50 B:0.001～ 0.010 Ti:0.65～ 1.15 B≤0.006

a

Refer to table 19. Unless otherwise specified, it is permissible to analyze niobium only.

b

22

GB/T XXXX-XXXX 6.1.2 The content of residual elements in the steel shall be in accordance with table 19.

Table 19 The content of residual elements in the steel group

Melting method

1

EAF

2

EAF+VD

Chemical P Advanced quality non-alloy tool steels Other steel types Cold-work tool steels Advanced quality non-alloy tool steels Other steel types

composition（mass percentage）/%, S Advanced quality non-alloy 0.030 tool steels 0.030 Other steel types Cold-work tool steels 0.030 Advanced quality non-alloy tool steels 0.025 Other steel types

up to Cu

Cr

Ni

0.020 0.030 0.020

0.25 0.25 0.25

0.025 EAF+ESR 3 0.025 0.010 VAR For non-alloy tool steels used for manufacturing wires forlead bath quenching, the residual chromium, nickel and copper content shall be no more than 0.10%, 0.12% and 0.20% respectively, and the sum of the three elements shall be no more than 0.40%.

6.1.3

The inspection of Pb, As, Sn, Sb, Bi, H, O and N is possible if agreed upon between

purchaser and supplier, and detailed requirements shall be noted in the contract.

6.2

Melting method The steels shall be melted by EAF, EAF+VD, EAF+ESR, VAR or other methods that can meet

customer requirements. The melting method used shall be noted in the contract.

6.3 6.3.1

Delivery condition The tool steel products are generally delivered in annealed condition, except for

SM45 、 SM50 、 SM55 、 2Cr25Ni20Si2 and 7Mn15Cr2Al3V2Mo, which are generally delivered in hot rolled or hot forged condition. The non-alloy tool steels can be delivered in annealed and cold drawn condition. 6.3.2

If required by the purchaser and noted in the contract, plastic mould steels, hot-

work tool steels, cold-work tool steels and special-purpose tool steels can be delivered in pre-hardened condition.

6.4 6.4.1

Hardness The hardness of the steel products in delivery condition and the as-quenched

hardness of the specimens shall conform to the requirements of table 20 to 27. The inspection of as-quenched hardness of the specimens can be omitted provided that the requirements of table 20 to 27 can be guaranteed by the supplier. 23

GB/T XXXX-XXXX 6.4.2

For annealed steel products whose section dimension is smaller than 5mm, the test of

hardness is unnecessary. When required by the purchaser, other tests such as tensile test may be performed and the technical requirement shall be agreed upon between purchaser and supplier.

Table 20 Hardness in delivery condition and specimen as-quenched hardness of unalloyed steels for cutting tools and moulds As-quenched hardness of the specimens

S.N.

Uni-code

Grades

Hardness of steel products delivered in annealed condition HBW，≤

1-1

TOO070

T7

187

800～820

1-2

TOO080

T8

187

780～800

Water

62

780～800

Water

62

Quenching temperature ℃

Rockwell Quenching hardness HRC medium ≥ Water 62

1-3

T01080

T8Mn

187

1-4

TOO090

T9

192

760～780

Water

62

1-5

TOO100

T10

197

760～780

Water

62

1-6

TOO110

T11

207

760～780

Water

62

1-7

TOO120

T12

207

760～780

Water

62

T13

217

760～780

Water

62

1-8

TOO130

The Brinell hardness of non-alloy tool steels in annealed and cold drawn condition shall be not higher than HBW 241.

Table 21 Hardness in delivery condition and specimen as-quenched hardness of steels for measuring tools and cutting tools

S.N.

Uni-code

Grades

Hardness of steel products delivered in annealed condition HBW

2-1

T30219

9SiCr

197～241

2-2

T30108

8MnSi

2-3

T30200

2-4 2-5

a

As-quenched hardness of the specimens Quenching temperature ℃

Rockwell Quenching hardness HRC medium ≥

820～860

oil

62

≤229

800～820

oil

60

Cr06

187～241

780～810

water

64

T31200

Cr2

179～229

830～860

oil

62

T31209

9Cr2

179～217

820～850

oil

62

2-6 T30800 W 187～229 800～830 water 62 When required by the purchaser and noted in the contract, the hardness of steels for threading tools shall be HBW187～HBW229. a

24

GB/T XXXX-XXXX

Table 22 Hardness in delivery condition and specimen as-quenched hardness of shock-resisting tool steels Unicode

Hardness of steel products delivered in annealed condition HBW

As-quenched hardness of the specimens

Rockwell Quenching hardness HRC medium ≥ 3-1 T40294 4CrW2Si 179～217 860～900 oil 53 3-2 T40295 5CrW2Si 207～255 860～900 oil 55 3-3 T40296 6CrW2Si 229～285 860～900 oil 57 Preheating at 667℃±15℃，heating at 885℃（salt bathing） or 900℃ a 3-4 T40356 6CrMnSi2Mo1V ≤229 （controlled atmosphere furnace） 58 ±6℃, holding for 5min～15min, oil cooling, tempering at 58℃～204℃ Preheating at 667℃±15℃, heating at 941℃（salt bathing） or 955℃ a 3-5 T40355 5Cr3MnSiMo1V ≤235 （controlled atmosphere furnace） 56 ±6℃, holding for 5min～15min, oil cooling, tempering at 56℃～204℃ 3-6 T40376 6CrW2SiV ≤225 870～910 oil 58 Note: Holding time means the preserving time when the specimen was heated to the required temperature. a The holding time of the specimen is 5 minutes in the salt bath, and 5-15 minutes in the controlled atmosphere furnace. S.N.

Grades

Quenching temperature ℃

Table 23 Hardness in delivery condition and specimen as-quenched hardness of steels for rollers As-quenched hardness of the specimens

Grades

Hardness of steel products delivered in annealed condition HBW

Quenching temperature ℃

Quenching medium

Rockwell hardness HRC ≥

T42239

9Cr2V

≤229

830～900

air

64

4-2

T42309

9Cr2Mo

≤229

830～900

air

64

4-3

T42319

9Cr2MoV

≤229

880～900

air

64

900～920

air

64

930～950

air

64

S.N.

Unicode

4-1

4-4 4-5

T42518 T42519

8Cr3NiMoV 9Cr5NiMoV

≤269 ≤269

Table 24 Hardness in delivery condition and specimen as-quenched hardness of cold-work tool steels S.N.

Uni-

Grades

Hardness of

As-quenched hardness of the specimens

25

GB/T XXXX-XXXX code

5-1 5-2 5-3 5-4 5-5 5-6

T20019 T20299 T21290 T20250 T21347 T21355

9Mn2V 9CrWMn CrWMn MnCrWV 7CrMn2Mo 5Cr8MoVSi

steel products delivered in annealed condition HBW ≤229 197～241 207～255 ≤255 ≤235 ≤229

Quenching temperature ℃

Rockwell Quenching hardness HRC medium ≥

780～810 oil 62 800～830 oil 62 800～830 oil 62 790～820 oil 62 820～870 air 61 1000～1050 oil 59 870℃～900℃,oil cooling or air cooling, 5-7 T21357 7CrSiMnMoV ≤235 60 Tempering at 150℃±10℃,air cooling Oil or 5-8 T21350 Cr8Mo2SiV ≤255 1020～1040 62 air 5-9 T21320 Cr4W2MoV ≤269 960～980or 1020～1040 Oil 60 5-10 T21386 6Cr4W3Mo2VNb ≤255 1100～1160 Oil 60 5-11 T21836 6W6Mo5Cr4V ≤269 1180～1200 Oil 60 Preheating at 730℃～840℃，heating at 64（salt 1210℃～1230℃（salt bathing or controlled bathing） atmosphere furnace）, holding for 5min～ 5-12 T21830 W6Mo5Cr4V2a ≤255 63（controlled 15min, oil cooling, tempering at 540℃～ atmosphere 560℃ for twice（salt bathing or controlled furnace） atmosphere furnace）, each time 2 hours 5-13 T21209 Cr8 ≤255 920～980 Oil 63 5-14 T21200 Cr12 217～269 950～1000 Oil 60 5-15 T21290 Cr12W ≤255 950～980 Oil 60 Oil or 5-16 T21317 7Cr7Mo2V2Si ≤255 1100～1150 60 air Preheating at 790℃±15℃, heating at 940℃ （salt bathing）or 950℃（controlled a 5-17 T21318 Cr5Mo1V ≤255 atmosphere furnace）±6℃, holding for 60 5min～15min, oil cooling; tempering at 200℃ ±6℃, holding for 2 hours 5-18 T21319 Cr12MoV 207～255 950～1000 Oil 58 Preheating at820℃±15℃, heating at 1000℃ (salt bathing) ±6℃ or 1010℃(controlled b 5-19 T21310 Cr12Mo1V1 ≤255 atmosphere furnace), holding for 10min～ 59 20min, air cooling, tempering at 200℃±6℃, holding for 2 hours Note: Holding time means the preserving time when the specimen was heated to the required temperature. a The holding time of the specimen is 5 minutes in the salt bath, and 5-15 minutes in the controlled atmosphere furnace. b The holding time of the specimen is 10 minutes in the salt bath, and 10-20 minutes in the controlled atmosphere furnace.

Table 25 Hardness in delivery condition and specimen as-quenched hardness of hot-work tool steels

S.N.

Unicode

Grades

Hardness of steel products delivered in annealed condition HBW

6-1

T22345

5CrMnMo

197～241

As-quenched hardness of the specimens Rockwell Quenching temperature Quenching hardness ℃ medium HRC ≥ b 820～850 oil 26

GB/T XXXX-XXXX 6-2

T22505

5CrNiMo

197～241

830～860

oil

b

6-3

T23504

4CrNi4Mo

≤285

840～870

Oil or air

b

6-4

T23514

4Cr2NiMoV

≤220

910～960

oil

b

6-5

T23515

5CrNi2MoV

≤255

850～880

oil

b

6-6

T23535

5Cr2NiMoVSi

≤255

960～1010

oil

b

6-7

T42208

8Cr3

207～255

850～880

oil

b

6-8

T23274

4Cr5W2VSi

≤229

1030～1050

Oil or air

b

6-9

T23273

3Cr2W8V

≤255

1075～1125

oil

b

a

≤229

Preheating at 790℃±15℃, heating at 1010℃（salt bathing）or 1020℃ （controlled atmosphere furnace）±6℃, holding for 5min～15min, oil cooling， tempering at 550℃±6℃ for twice, each time 2 hours Preheating at 790℃±15℃，heating at 1000℃（salt bathing）or 1010℃ （controlled atmosphere furnace）±6℃, holding for 5min～15min, oil cooling, tempering at 550℃±6℃ for twice, each time 2 hours Preheating at 790℃±15℃, heating at 1010℃（salt bathing）or 1020℃ （controlled atmosphere furnace）±6℃, holding for 5min～15min, oil cooling, tempering at 550℃±6℃ for twice, each time 2 hours

b

6-10

T23352

4Cr5MoSiV

6-11

T23353

4Cr5MoSiV1

a

≤229

6-12

T23354

4Cr3Mo3SiV

a

≤229

6-13

T23355

5Cr4Mo3SiMnVA1

≤255

1090～1120

b

b

6-14

T23364

4CrMnSiMoV

≤255

870～930

oil

b

6-15

T23375

5Cr5WMoSi

≤248

990～1020

oil

b

6-16

T23324

4Cr5MoWVSi

≤235

1000～1030

Oil or air

6-17

T23323

3Cr3Mo3W2V

≤255

1060～1130

oil

b

6-18

T23325

5Cr4W5Mo2V

≤269

1100～1150

oil

b

6-19

T23314

4Cr5Mo2V

≤229

1000～1030

oil

b

6-20

T23313

3Cr3Mo3V

≤229

1010～1050

oil

b

b

b

b

Oil or b air b 6-22 T23393 3Cr3Mo3VCo3 ≤229 1000～1050 oil Note: Holding time means the preserving time when the specimen was heated to the required temperature. a The holding time of the specimen is 5 minutes in the salt bath, and 5-15 minutes in the furnace controlled atmosphere. b Measured for reference if required by purchaser and noted in the contract. 6-21

T23314

4Cr5Mo3V

≤229

1000～1030

Table 26 Hardness in delivery condition and specimen as-quenched hardness of plastic mould steels S.N.

Unicode

Grades

Hardness of steel products in delivery condition

As-quenched hardness of the specimens

27

GB/T XXXX-XXXX

7-1

T10450

SM45

7-2

T10500

SM50

7-3

T10550

SM55

7-4 7-5 7-6 7-7 7-8

T25303 T25553 T25344 T25378 T25515

3Cr2Mo 3Cr2MnNiMo 4Cr2Mn1MoS 8Cr2MnWMoVS 5CrNiMnMoVSCa

As-annealed Pre-hardened Rockwell Quenching temperature Quenching hardness hardness hardness HRC ℃ medium HBW, ≤ HRC ≥ Hardness in hot rolled － － － condition: 155～215 Hardness in hot rolled － － － condition: 165～225 Hardness in hot rolled － － － condition: 170～230 235 28～36 850～880 Oil 52 235 30～36 830～870 Oil or air 48 235 28～36 830～870 Oil 51 235 40～48 860～900 Air 62 255 35～45 860～920 Oil 62

7-9

T25512

2CrNiMoMnV

235

30～38

850～930

Oil or air

48

7-10

T25572

2CrNi3MoAl

－

38～43

－

－

－

7-11

T25611

1Ni3MnCuMoAl

－

38～42

－

－

－

7-12

A64060

06Ni6CrMoVTiAl

255

43～48

7-13

A64000

00Ni18Co8Mo5TiAl

As negotiated

As negotiated

7-14 7-15 7-16 7-17 7-18 7-19 7-20

S42023 S42043 T25444 T25402 T25303 T25513

2Cr13 4Cr13 4Cr13NiVSi 2Cr17Ni2 3Cr17Mo 3Cr17NiMoV

220 235 235 285 285 285

S44093

9Cr18

255

S46993

9Cr18MoV

269

30～36 30～36 30～36 28～32 33～38 33～38 As negotiated As negotiated

7-21

Solution at 850℃～880℃, oil or air cooling Measured for Aging at 500℃～540℃, air reference cooling Solution at 805℃～825℃, air cooling As negotiated Aging at 460℃～530℃, air cooling 1000～1050 oil 45 1050～1100 oil 50 1000～1030 oil 50 1000～1050 oil 49 1000～1040 oil 46 1030～1070 oil 50 1000～1050

oil

55

1050～1075

oil

55

Table 27 Hardness in delivery condition and specimen as-quenched hardness of special-purpose tool steels Hardness of steel products in delivery condition S.N.

Unicode

Grades

As-annealed hardness HBW

8-1

T26377 7Mn15Cr2Al3V2WMo

－

8-2

S31049

2Cr25Ni20Si2

－

8-3

S51740

0Cr17Ni4Cu4Nb

To be negotiated

8-4

H21231 Ni25Cr15Ti2MoMn

≤300

As-quenched hardness of the specimens

Heat treatment process Solution at 1170℃～1190℃, water cooling Aging at 650℃～700℃, air cooling Solution at 1040℃～1150℃, water or air cooling Solution at 1020℃～1060℃, air cooling Aging at 470℃～630℃, air cooling Solution at950℃～980℃, water or

Rockwell hardness HRC ≥ 45 a

a

a

28

GB/T XXXX-XXXX air cooling,Aging at720℃+620℃, air cooling Solution at980℃～1000℃, water, 8-5 H07718 Ni53Cr19Mo3TiNb ≤300 oil or air cooling Aging at 710℃～730℃, air cooling a Measured for reference if required by purchaser and noted in the contract.

6.5

a

Macrostructure

6.5.1

The steel products shall be tested for their macroetch structure, and macroech

slices shall be free from visible defects such as shrinkage, inclusions, lamination, cracks, bubbles, and flakes. The severity levels for center porosity and ingot pattern, rated according to annex A, figure A.1 and A.2, shall meet the following requirements: a)The severity levels for center porosity and ingot pattern of rounds and squares shall meet class 2 requirement of table 28. b) The severity levels for center porosity and ingot pattern of flats shall meet class 2requirement of table 29. c) When required by purchaser and agreed upon between purchaser and supplier, the steel products can be delivered according to class 1 requirement in table 28 and 29, which need to be noted in the contract.

Table 28 The macroetch defects and acceptable severity levels of rounds and squares Class 1

Class 2

Diameter or side length of steel products mm

Center porosity

≤80

2.0

2.0

3.0

3.0

＞80～150

2.5

3.0

3.5

3.0

＞150～250

3.0

3.0

4.0

4.0

＞250～400

3.5

3.0

4.5

4.0

＞400

As negotiated

As negotiated

As negotiated

As negotiated

Ingot pattern

Center porosity

Ingot pattern

Rating level，maximum

Table 29 The macroetch defects and acceptable severity levels of flats Class 1

Class 2

Diameter or side length of steel products mm

Center porosity

≤80

2.0

2.0

3.0

3.0

＞80～150

2.5

3.0

3.5

3.0

＞150～250

3.0

3.0

4.0

4.0

＞250～400

3.5

3.0

4.5

4.0

Ingot pattern

Center porosity

Ingot pattern

Rating level，maximum

29

GB/T XXXX-XXXX

＞400

Thickness of steel products mm Hot rolled flats

Forged flats

6.5.2

As negotiated between purchaser and supplier

As negotiated between purchaser and supplier

As negotiated between purchaser and supplier

Class 1 Center porosity

As negotiated between purchaser and supplier

Class 2 Ingot pattern

Center porosity

Ingot pattern

Rating level，maximum

≤60

3.0

3.0

4.0

4.0

60～120

3.5

3.0

4.5

4.0

＞120

As negotiated

As negotiated

As negotiated

As negotiated

160～250

3.0

3.0

4.0

4.0

＞250～400

3.5

3.0

4.5

4.0

＞400

As negotiated

As negotiated

As negotiated

As negotiated

When agreed upon between purchaser and supplier and noted in the contract, the

macrostructure of steel products can be tested in accordance with GB/T 1979, and the acceptable severity levels shall be negotiated between purchaser and supplier. 6.5.3

When agreed upon between purchaser and supplier and noted in the contract, the

macrostructure of electroslag remelted steels can be tested according to ASTM A604, and the acceptable severity levels shall be negotiated between purchaser and supplier.

6.6

Microstructure

6.6.1 Pearlite structure 6.6.1.1

Steels such as 9SiCr, Cr2, Cr06, 9Cr2, W, 9CrWMn, CrWMn and 7CrMn2Mosupplied in

annealed condition are subject to the inspection and rating of pearlite structure in accordance with figure A.3, and severity level1 to 5 are acceptable. When required by purchaser and noted in the contract, 9SiCr in annealed condition and used for making threading tools shall have pearlite structure of severity level 2 to 4. 6.6.1.2

Non-alloy tool steels in annealed condition and with section dimension up to 60mm

shall be subject to the inspection and rating of pearlite structure in accordance with figure A.4, and the acceptable severity levels shall conform to the requirement of table 30. When required by purchaser, the non-alloy tool steels with section dimension bigger than 60mm can be tested for the pearlite structure and the acceptable severity levels shall be negotiated between purchaser and supplier.

Table 30 Acceptable severity levels of pearlite structure of non-alloy tool steels 30

GB/T XXXX-XXXX Grades T7、T8、T8Mn、T9 T10、T11、T12、T13

6.6.1.3

Acceptable severity levels, grade 1～5 2～4

Steels used for hot pressure work are not subject to the inspection of pearlite

structure. 6.6.2 Carbide network 6.6.2.1

Steels such as 9SiCr, Cr06, Cr2 and CrWMn supplied in annealed condition are

subject to the inspection and rating of carbide network in accordance with the rating chart in figure A.5 and the acceptable severity levels shall be as follow: a) For steels with section dimension up to 60mm, the maximum acceptable severity level is class 3. When required by purchaser and noted in the contract, the maximum acceptable severity level for 9SiCr used for threading tools is class 2. b) The acceptable severity levels for flats and other forms with section dimension bigger than 60mm shall be agreed upon between purchaser and supplier. 6.6.2.2

Non-alloy tool steels delivered in annealed condition (except for T7 and T8) are

subject to the inspection and rating of carbide network in accordance with the rating charts in figure A.6 and the acceptable severity levels shall be in accordance with table 31.

Table 31 Maximum acceptable severity levels of carbide network of non-alloy tool steel Nominal dimensions of steel products/mm ≤60 ＞60～100 ＞100

Maximum acceptable severitylevels, class 2 3 As negotiated

6.6.2.3 Non-alloy tool steels such as T7 and T8, as well as steels for hot pressure work are not subject to the inspection of carbide network. 6.6.3 Eutectic carbide segregation 6.6.3.1

Steels such as Cr8Mo2VSi, 6Cr4W3Mo2VNb, 6W6Mo5Cr4V, W6Mo5Cr4V2, Cr8, Cr12, Cr12W,

Cr12MoV and Crl2Mo1V1supplied in annealed condition are subject to the inspection and rating of eutectic carbide segregation according to GB/T 14979-1994, plate 4, and the acceptable severity levels shall conform to the class 2 requirement in table 32. When required by purchaser and noted in the contract, the acceptable severity levels can be in accordance with class 1.

31

GB/T XXXX-XXXX Table 32 the acceptable severity levels of eutectic carbide segregation of cold work tool steel

a

Acceptable severity levels of eutectic carbide segregation Class1 Class2

Diameter or side length mm

Severity level, maximum

≤50

3

4

＞50～70

4

5

＞70～120

5

6

＞120～400

6

As negotiated

＞400

As negotiated

As negotiated

a

The acceptable severity level of flats shall be agreed upon between purchaser and supplier.

6.6.3.2 Steel6Cr4W3Mo2VNb can be exempted from the above inspection provided that the supplier guarantees that the requirement for eutectic carbide segregation can be met.

6.7

Non-metallic inclusions

6.7.1 For eletroslag remelted steels, the non-metallic inclusions shall be tested and rated in accordance with GB/T 10561-2005, method A, and the severity levels shall conform to class 1 requirement in table 33. 6.7.2 For vacuum degassing steels, the non-metallic inclusions shall be tested and rated in accordance with GB/T 10561-2005, method A, and the severity levels shall conform to class 2 requirement in table 33. 6.7.3 Steels melted with other methods can be tested for the non-metallic inclusions when required by the purchaser, and the acceptable severity levels shall be agreed upon between purchaser and supplier.

Table 33 Acceptable severity levels for non-metallic inclusions Class1 Type A

a

Thin 1.5

Class2 Heavy Thin Severity levels, up to 1.5

2.5

Heavy 2.0

B 1.5 1.5 2.5 2.0 C 1.0 1.0 1.5 1.5 D 2.0 1.5 2.5 2.0 When required by purchaser, the type DS inclusion can be inspected, and the acceptable severity level shall be agreed upon between purchaser and supplier. a

Free cutting plastic mould steels such as 4Cr2Mn1MoS, 8Cr2MnWMoVS and 5CrNiMnMoVSCa are exempted from the inspection of type A inclusion.

32

GB/T XXXX-XXXX 6.8

Decarburization

6.8.1

The

depth

of

total

decarburization

(ferrite

decarburization

+

partial

decarburization) on each side of hot rolled and forged steel products shall be in accordance with class 2 requirement in table 34. When required by purchaser, and agreed upon between purchaser and supplier, class 1 will be adopted , which shall be noted in the contract.

Table 34 The depth of total decarburization of hot rolled and forged steel products Diameter or side length of the steel product 5～150

in millimeter

The depth of total decarburization, maximum Class1 Class2 O.25+1%D

＞150

0.20+2%D As negotiated

Note: D is the nominal section dimension of the steel product.

6.8.2

The depth of total decarburization on each side of cold drawn steel products shall

be in accordance with the requirement of table 35.

Table 35 The depth of total decarburization of cold drawn steel products in millimeter Steel type

Group

≤16mm ＞16mm used for high frequency quenching Silicon free steel Others Silicon containing steel Note: D is the nominal section dimension of the steel product. Non-alloy tool steels

6.8.3

The depth of total decarburization, maximum 1.5%D 1.3%D 1.0%D 1.5% of nominal dimension 2.0% of nominal dimension

The decarburization depth of flats may be inspected when required by purchaser and

the detailed requirement shall be agreed upon between purchaser and supplier. 6.8.4 Bright steels shall be free from decarburization on the surface. 6.8.5

The decarburization requirement for 6W6Mo5Cr4V, 4Cr3Mo3SiV and 3Cr3Mo3W2V shall be

agreed upon between purchaser and supplier. 6.8.6

The non-magnetic mould steel 7Mn15Cr2Al3V2WMo is not subject to the inspection of

decarburization. 33

GB/T XXXX-XXXX

6.9

Relative permeability

The relative permeability of non-magnetic mould steel 7Mn15Cr2Al3V2WMo shall be less than 1.01. The inspection may be omitted if the supplier guarantees that the above requirement can be met.

6.10

Ultrasonic testing

6.10.1

The steel products shall be ultrasonic tested according to GB/T6402 and shall be

free from internal metallurgical defects such as flakes, slag inclusions, lamination, internal cracks and shrinkage. 6.10.2

The allowable limit of indications shall be in accordance with the size classes in

table 36 and the frequency classes in table 37. The acceptable classes shall be in accordance with table 38, group 2, while for some high quality steels such as electroslag remelted steels, the acceptable classes shall be in accordance with group1. 6.10.3

The acceptable classes for special-purpose mould steels shall be agreed upon

between purchaser and supplier.

Table 36 Size classes for allowable limit values of the indications Indication without a

Size class

A B C D E a

prolongation Diameter of circular disk reflector, in mm 14 10 7 5 3

Indication with b

Maximum length of

prolongation Diameter of circular disk reflector, in mm

prolongation mm

10 7 5 3 2

80 60 40 30 30

c

Depending onthe classes required by the purchase order, indication without prolongation should have a distance of at least 5 times of circular disk reflector depending on size. If distances are shorter, the indications shall be regarded as “indications with prolongations”

b

For circular disk reflector,the classification of size classes is based on amplitude differences of around 6 dB. c

如果最大连续缺陷长度超过标准级别，可考虑增加数量等级。例如：缺陷连续长度为 160mmA 级，则数量等级为 160：80=2。Oversteps of maximum prolongation can be taken into account by agreement with addition of allowable frequency. It corresponds to the indication with prolongation, e.g. for 160mm length in 34

GB/T XXXX-XXXX size class A: a frequency of 160:80 = 2.

Table 37 Classes of frequency (of occurrence) Frequency class a b c d e

Number of indications without Number of indications with prolongation prolongation Allowable limit 32 16 16 8 8 4 4 2 2 1

Table 38 Acceptable classes for UT diameter, side length or thickness mm a

≤150 ＞150～250 ＞250～400 ＞400

Acceptable classes Group 1

Group 2

E/e

E/d

E/d D/d C/c

D/d C/c B/b

a

When the quality of the steel can be ensured by the supplier, UT can be omitted or performed on intermediate billets instead of finished products.

6.11 6.11.1

Surface quality For hot rolled and forged steel products used for pressure work, the surface shall

be free from visible imperfections such as seams, laps, scab or inclusions. Any of the above imperfections shall be removed and the maximum depth of removal, where the actual dimension of the product is taken as the zero line, shall comply with Table 39. The width of removal shall be no less than 5 times of the depth of removal. It is permissible to have small surface imperfections with depth of no more than half of the dimension tolerances. Table 39 Surface quality requirement for steels for pressure work Diameter, side length, thickness or width

Maximum depth of removal

＜80

1/2 of the dimensional tolerance

6.11.2

≥80～140

Dimensional tolerance

＞140

4% of the nominal section dimension

in mm

For hot rolled and forged steel products used for cut work, it is permissible to

have local surface imperfections with the depth specified in Table 40, where the nominal dimension is taken as the zero line for calculating the depth of imperfections and the minimum dimension of the product shall be guaranteed. Table 40 Permissible maximum depth of local imperfections

Unit: mm 35

GB/T XXXX-XXXX Diameter, side length, thickness or width

Maximum depth of local imperfections

＜80

1/2 of the dimensional tolerance

≥80

Dimensional tolerance

6.11.3

The surface of cold drawn steels shall be clean and smooth, free of defects such as

cracks, laps, scab, inclusions and scales, and meet the following requirements: a) For cold drawn steels with tolerance classes of h9 and h10, the surface must be free from any defects; b) For cold drawn steels with tolerance classes of h11 and h12, it is permissible to have minor surface defects such as pitting, scratches, hairlines, dents, dark spots, pull cracks and lubricant marks, the depth of which shall be smaller than or equal to the dimensional tolerance, where the actual dimension of the product is taken as the zero line. When required by the purchaser and noted in the contract, the permissible depth of the defects can be no more than half of the dimensional tolerance. c) For cold drawn and heat-treated steels, it is permissible to have oxidation color or slight oxidation layer on the surface. 6.11.4

The surface of bright steels shall be in conformance with the requirement of

GB/T3207-2008. 6.11.5

Steels delivered in machined condition shall have clean and smooth surfaces without

having defects such as cracks, laps, scab and scales. If any, local grinding is permissible provided that the minimum size of the final product can be guaranteed.

6.12

Special requirements

When required by the purchaser, and agreed upon between purchaser and supplier,the following inspection items can be addedwhich shall be noted in the contract: a) Special chemical composition requirement; b) Special hardness requirement; c) Special requirement for dimensions and dimensional tolerances; d) Grain size; e) Hardenability ; f) Other requirements.

7 Test methods

36

GB/T XXXX-XXXX The test items and test methods used for each lot shall conform to the requirement of table 41.

8 Inspection rules 8.1

Inspection and acceptance The inspection and acceptance of the quality of the steel products are left to

supplier’s Technical and Quality Supervision Department, and the purchaser reserves the right to recheck any specified item in this standard or in contract.

8.2

Lot rules

8.2.1

The steel products shall be inspected in lots, and each lot consists of steel

products of the same heat number, the same working method to be used by end users, the same delivery condition, the same size, and the same heat treatment batch. 8.2.2

For electroslag remelted steels, one lot consists bars of the same remelting heat

number, the same working method to be used by end users, the same delivery condition, the same size, and the same heat treatment batch. If the manufacturing process is stable and the requirements of this standard can be guaranteed, a lot can be the products of the same mother heat number, while the chemical composition shall be inspected for each remelting heat number, and other test items shall be sampled according to the requirement of EAF melts.

8.3

Sampling quantity and position The sampling quantity and position for each lot of the steel products shall comply with

the requirement of table 41.

Table 41 Test items, sampling position, sampling quantity and test methods for steel products a

S.N.

Test items

Sampling quantity EAF steels ESR steels VD steels VAR steels

Sampling position

Test methods

37

GB/T XXXX-XXXX

GB/T 20066

GB/T 223（see chapter 2）,GB/T4336,GB/T11261,GB/T 20123,GB/T 20124

On different bars

GB/T231.1

1

Chemical composition

2

As-delivery hardness

3

Specimen hardness

2

1

4

Macrostructure

2

1

5

Pearlite structure

2

1

GB/T 13298, Annex A

6

Carbide network

2

1

GB/T 13298,Annex A

2

1

2

1

GB/T 10561-2005

2

1

GB/T 224

1

1

Randomly

GJB 937-1990

— 1 Each bar Each bar Each bar

1 1 Each bar Each bar Each bar

Randomly Randomly The whole steel bar The whole steel bar The whole steel bar

GB/T 6394 GB/T 225 or Annex B GB/T 6402 visually Caliper, micrometer

Eutectic carbide segregation Non-metallic

7

8

inclusions

b

Depth of decarburization Relative permeability Grain size Hardenability UT Surface quality dimensions

9 10 11 12 13 14 15 a b

1 per heat

1 per heat

5% of the lot，and no less than 5 pieces

EAF or VD steels: On different bars ESR or VAR steels: randomly EAF or VD steels: On different steel billet or bar representing the head of the ingot ESR or VAR steels: On steel billet or bar representing the head of the ingot

EAF or VD steels: On different bars ESR or VAR steels: randomly

GB/T230.1

GB/T 226, Annex A GB/T 1979 or ASTM A604

GB/T 13298 GB/T 14979-1994

When the delivery amount is less than the sampling amount, take samples on each bar. For large size bars, a rough specimen with diameter or side length of 90-120mm can be forged from the bar for non-metallic inspection. When agreed upon between purchaser and supplier and noted in the contract, other test methods can be used.

8.4

Retest and quality judgement rules

8.4.1

The retest and quality judgement rules of the steel products shall comply with GB/T

17505. 8.4.2

If conformity is ensured by the supplier, it is permissible to take samples from

intermediate billet instead of final product or from larger bars instead of the small ones of the same heat for macrostructure, non-metallic inclusions and specimen quenched hardness inspection. 9 Packaging, marking and certificate of quality The packaging, marking and certificate of quality of the steel products shall comply with GB/T 2101. 38

GB/T XXXX-XXXX

39

GB/T XXXX-XXXX Annex A (Normative) 1）

Standard rating photographs A.1

Class 1 Macrostructure

A.1.1 Figure A.1 shows the standard rating photographs for center porosity

Severity 1

40

GB/T XXXX-XXXX

Severity 2

Severity 3

41

GB/T XXXX-XXXX

Severity 4

Severity 5

42

GB/T XXXX-XXXX

Severity 6

Fig. A.1 Standard rating photographs for center porosity

A.1.2

Figure A.2 shows the standard rating photographs for ingot pattern

43

GB/T XXXX-XXXX

Severity 1

Severity 2

44

GB/T XXXX-XXXX

Severity 3

Severity 4

45

GB/T XXXX-XXXX

Severity 5

Severity 6

Fig. A.2 Standard rating photographs for ingot pattern

46

GB/T XXXX-XXXX

A.2 A.2.1

Class 2 Pearlite structure Figure A.3 shows the standard rating photographs for pearlite structure of alloy

tool steels.

Severity 1

Severity 3

Severity 2

Severity 4

47

GB/T XXXX-XXXX

Severity 5

Severity 6

Note: The diameter of the field is 80mm, and 100μm represents 10mm.

Fig. A.3 Standard rating photographs for pealite structure of alloy tool steels

A.2.2

Figure A.4 shows the standard rating photographs for pearlite structure of non-alloy

tool steels.

Severity 1

Severity 2

48

GB/T XXXX-XXXX

Severity 3

Severity 4

Severity 5

Severity 6

Note: The diameter of the field is 65mm, and 100μm represents 10mm.

Fig. A.4 Standard rating photographs for pealite structure of non-alloy tool steels

A.3

Class 3 Carbide network

A.3.1

Figure A.5 shows the standard rating photographs for carbide network of alloy tool

steels. 49

GB/T XXXX-XXXX

Severity 1

Severity 2

Severity 3

Severity 4

Note: The diameter of the field is 80mm, and 100μm represents 10mm.

Fig. A.5 Standard rating photographs for carbide network of alloy tool steels

A.3.2

Figure A.6 shows the standard rating photographs for carbide network of non-alloy

tool steels.

50

GB/T XXXX-XXXX

Severity1

Severity2

Severity3

Severity4

Note: The diameter of the field is 65mm, and 100μm represents 10mm.

Fig. A.6 Standard rating photographs for carbide network of non-alloy tool steels

51

GB/T XXXX-XXXX

Annex B (Normative) Test methods for determining hardenability of non-alloy tool steels

B.1

Principle Heating the test piece to the quenching temperature, holding for a period of time, and

then quenching. The quenching depth shall be measured on a transverse cross section broken at the mid-point of the length of the test piece.

B.2

Symbols and designations Refer to table B.1 for the symbols and designations.

Table B.1 symbols and designations Symbols

L D H T e1

e2

e3 e

B.3

e4

Designations Total length of test piece Diameter of test piece Notch depth of test piece temperature of quenching medium the depth of the dark area on the etched surface quenching depth

Unit mm mm mm ℃ mm mm

Test piece

B.3.1

Preparation of rough specimen

The rough specimen shall be sampled to show the whole cross section of the ingot, billet and product. When necessary, the sampling of the rough specimen can be made by forging or rolling to diameter of 25mm. The sampling position shall be in accordance with GB/T 225. B.3.2 Pre-treatment of rough specimen B.3.2.1

For steel products delivered in normalized or annealed condition, it is

unnecessary to pre-treat the rough specimen. B.3.2.2

The rough specimen made by forging or rolling can be normalized or annealed

according to the heat treatment process recommended for the product.

52

GB/T XXXX-XXXX B.3.2.3

The rough specimen can also be quenched and tempered: the quenching temperature is

870℃±10℃, holding for a period of time and quenching in oil. Then holding for 1 hour at 625℃～650℃, cooling in still air. B.3.3 Preparation of test piece The rough specimen shall be machined into round test piece with diameter of 20mm±0.5mm and length of 75mm±0.5mm (see fig. B.1).If the standard test piece cannot be obtained from the product, test piece of smaller size is permissible and the size shall be noted.

Fracture surface

Notching after QT

Fig. B.1 schematic of test piece

B.4

Test method

B.4.1 Heating and quenching of test piece It is preferential to heat the test piece in salt bath, lead bath or controlled atmosphere furnace to avoid surface decarburization or oxidation. Heating in electric chamber furnace is also permissible. The test piece shall be heated uniformly to the agreed-upon temperature, and the holding period at the temperature is generally 10 to 30 minutes depending on the furnace type. The quenching medium is the 10% sodium chloride water solution. The solution shall be no less than 200L, and the temperature is 20℃±10℃. 53

GB/T XXXX-XXXX The test piece shall be put into the quenching medium immediately after taking out of the furnace. In order to ensure uniform cooling, keep on stirring the medium until the test piece cools down. B.4.2 Preparation of the cross section to be tested Machine a groove of 1.5-2mm deep on the test piece after cleaning and drying, and fracture the test piece on the side opposite the notch through bending or striking. Other physical methods can be used to fracture the test piece provided that no heat affection shall be generated. The fracture shall be grinded and polished , soaked in 50% HCL water solution at temperature of 80℃～85℃ for 3 minutes, flushed by hot water and blow-dryed. B.4.3

Measurement of quenching depth

The quenching depth of the steel shall be measured through measuring the depth of the dark area on the polished and etched surface. Two diameter symmetrically to the notch and in 90 degree shall be chosen for measurement (see figure B.2). The readings shall be accurate to 0.25mm, and the average of the 4 measurements shall be adopted:

e

e1  e2  e3  e4 4

Fig. B.2 Schematic for the measurement of quenching depth If any single measurement result differs from the average by more than 1mm, the result is deemed to be invalid, and the fracture surface shall be re-prepared or new test piece shall be prepared.

B.5

Expression of the result The quenching depth shall be expressed in millimeter and accurate to 0.5mm. When

different quenching temperatures are used for the test, the quenching depth shall be followed by quenching temperature in the bracket. 54

GB/T XXXX-XXXX Example: 3.5 (780℃) means that the quenching temperature is 780℃, and the quenching depth is 3.5mm. 4.0 (840℃) means that the quenching temperature is 840℃, and the quenching depth is 4.0mm.

55

GB/T XXXX-XXXX

Annex C (Informative) Main characteristics and applications of the steel grades The main characteristics and applications of the steel grades are shown in table C.1 to C.7.

Table C.1 Main characteristics and applications of non-alloy steels for cutting tools and moulds S.N.

Uni-code

Steel grade

1-1

TOO070

T7

Main characteristics and applications Hypoeutectoid steel with good plasticity, high toughness and strength, relatively high hardness, but poor machinability. It is resistant to vibration and shock load, Suitable for tools used under moderate shock load and requiring certain hardness and wear resistance and high toughness. With better hardenability and toughness than T10, high wear resistance but

1-2

TOO080

T8

low plasticity and strength. Quenching may lead to

overheat and big

deformation, and it is likely to have carbide network retained in large and medium dies. Suitable for small drawing and extruding dies. Eutectoid steel with relatively high hardenability and hardness, but low

1-3

T01080

T8Mn

plasticity and strength. Suitable for large-section woodworking tools, handsaw blades, engraving tools, rivet stamping dies, chisels for coal mining. Hypereutectoid steel with high hardness, low plasticity and strength.

1-4

TOO090

T9

Suitable for tools requiring high hardness and certain toughness such as engraving tools, rivet stamping dies, punches, woodworking tools and rock drilling tools. Non-alloy

1-5

TOO100

T10

tool

steel

with

good

comprehensive

properties,

high

wear

resistance and low overheating sensitivity. High strength and certain toughness can be obtained through proper heat treatment. Suitable for dies with high demands on wear resistance and suffering low shock load. Hypereutectoid steel with good comprehensive mechanical properties (e.g. hardness, wear resistance and toughness), and not prone to have grain growth and form carbide network during heating. Suitable for tools whose cutting

1-6

TOO110

T11

edge has no temperature increase during cutting, e.g. saw, screw tap, file, scraper,

reamer,

threading

die,

as

well

as

cold

stamping

dies

and

woodworking tools having no sharp change in cross section and whose size is not big. Hypereutectoid steel with excess carbide retained after quenching due to the high carbon content, resulting in high hardness and wear resistance, low toughness, and big quenching deformation. Suitable for tools not suffering 1-7

TOO120

T12

shock load, and whose cutting speed is not high and cutting edge has no temperature increase during cutting, e.g. turning tools, milling tools, drills, screw taps, files, scrapers, reamers and threading dies, as well as cold trimming dies and perforating dies whose cross section is small.

56

GB/T XXXX-XXXX Hypereutectoid steel with excess carbide retained after quenching due to the high carbon content, resulting in high hardness and low toughness. The poor mechanical properties due to the increase of carbide content and the 1-8

TOO130

T13

ununiform distribution of carbide make it not suitable for tools with high cutting speed and suffering shock load. Suitable for metal cutting tools not suffering shock load and requiring rather high hardness, e.g. shavers, scrapers, wire-drawing tools, files, knurling tools, tools for hard rock processing and engraving.

Table C.2 Main characteristics and applications of steels for measuring tools and cutting tools S.N.

Uni-code

Steel grade

2-1

T30219

9SiCr

2-2

T30108

8MnSi

2-3

T30200

Cr06

2-4

T31200

Cr2

2-5

T31209

9Cr2

2-6

T30800

W

Main characteristics and applications With higher hardenability and quenching hardness than chromium steels, and good temper resistance. Suitable for low speed cutting tools with complex configuration, small deformation, and high wear resistance requirement, e.g. drills, threading tools, manual reamer, thread rolling flat dies and thread rolling cylindrical dies; as well as cold work dies (e.g. stamping dies, impression blocks), cold rolls, straightening rolls and long and thin rods. Low-alloy tool steel by adding silicon and manganese into T8, with high temper resistance, high hardenability and wear resistance, and smaller heat treatment deformation than non-alloy tool steels. Suitable for woodworking tools, cold stamping dies and punches, as well as cold working dies. Steel by adding certain amount of chromium into non-alloy tool steels, with higher hardenability and wear resistance than non-alloy tool steels, good cold work plasticity and machinability. Suitable for woodworking tools, and cold working dies such as perforating dies and cold stamping dies. Steel by adding certain amount of chromium into T10, with higher hardenability, hardness and wear resistance than non-alloy tool steels, as well as high contact fatigue strength and small quenching deformation. Suitable for woodworking tools, cold stamping dies and punches, as well as medium and small cold working dies. With similar properties to and better toughness than Cr2 steels. Suitable for woodworking tools, cold rolls, cold stamping dies and punches, steel stamping and perforating dies. Steel by adding certain amount of tungsten into non-alloy tool steels, with higher hardness and wear resistance after heat treatment, low superheat sensitivity, small heat treatment deformation and good temper resistance. Suitable for small auger bits, screw taps, files, and threading dies, as well as tools whose working temperature and cutting speed are not high.

Table C.3 Main characteristics and applications of shock-resisting tool steels S.N. Uni-code

3-1

T40294

Steel grade

4CrW2Si

Main characteristics and applications Steel by adding certain amount of tungsten into chromium-silicon steels, with relatively high hardenability and high-temperature strength. Suitable for tools operating under high shock load, e.g. pneumatic tools, blanking and trimming compound dies, stamping dies, blanking and shearing tools such as shears for cold cutting, and some small hot working dies.

57

GB/T XXXX-XXXX Steel by adding certain amount of tungsten into chromium-silicon steels, with relatively high hardenability and high-temperature strength. Suitable 3-2

T40295

5CrW2Si

for cold shearing blades for metals, scraper knives for thread rolling dies, cold blanking and trimming dies, as well as woodworking tools for long-term operation. Steel by adding certain amount of tungsten into chromium-silicon steels, with high quenching hardness and certain high-temperature strength. Suitable

3-3

T40296

6CrW2Si

for tools operating under shock load and requiring high wear resistance, e.g. pneumatic tools, chisels, dies, cold shear blades, blanking and trimming dies, and tools for air hammer. Equivalent to S5 in ASTM A681, with high hardenability, wear resistance, and temper resistance. The quenching temperature of the steel is low, and the

3-4

T40356

6CrMnSi2Mo1V

dies seldom have problems of chipping and breakage. Suitable for tools, stamping dies, cold blanking and trimming dies operating under high shock load. Equivalent to S7 in ASTM A681, with good hardenability, high strength and

3-5

T40355

5Cr3MnSiMo1

temper resistance, as well as comprehensive properties. Suitable for tools and stamping dies operating under high temperature and high shock resistance, as well as hammer forging dies. Oil-quenched shock-resisting medium carbon cold work tool steel with good

3-6

T40376

6CrW2SiV

combination of shock resistance and wear resistance, as well as high fatigue resistance and dimensional stability. Suitable for blades, cold forming tools, precision blanking dies and thermal perforating tools.

Table C.4 Main characteristics and applications of steels for rollers S.N.

Uni-code

Steel grade

Main characteristics and applications A 2%chromium series steel with high carbon content that ensures high hardness of the rollers; by adding chromium, the hardenability of the steel

4-1

T42239

9Cr2V

is increased, and by adding vanadium, the wear resistance is improved and the grain size is refined. Suitable for cold work rolls and supporting rolls. A 2%chromium series steel with high carbon content that ensures high hardness of the rollers; by adding chromium and molybdenum, the hardenability and wear resistance are improved. The steel has good

4-2

T42309

9Cr2Mo

forgeability, and by controlling low final forging temperature and appropriate deformation, the grain size of the steel can be refined, the carbide network along the grain boundary can be eliminated and the carbide are uniformly distributed. Suitable for cold work rolls, supporting rolls and straightening rolls. A 2%chromium series steel with better comprehensive properties than 9Cr2

4-3

T42319

9Cr2MoV

series steels. The properties of the roller billet will be improved if the steel is remelted by ESR process. Suitable for cold work rolls, supporting rolls and straightening rolls.

58

GB/T XXXX-XXXX A 3%chromium series steel, and the depth of hardening can be up to 30mm 4-4

T42518

8Cr3NiMoV

after quenching and subzero treatment. Suitable for cold work rolls, and the service life is longer than 2%chromium series steels. Equivalent to MC5, with high hardenability and good wear resistance, and the

4-5

T42519

9Cr5NiMoV

depth of hardening on each side of the rollers can be up to 35-40mm (≥ HSD85). Suitable for cold work rolls whose working condition is bad and requiring deep hardening depth and accident resistance.

Table C.5 Main characteristics and applications of cold work tool steels S.N. Uni-code

Steel grade

5-1

T20019

9Mn2V

5-2

T20299

9CrWMn

5-3

T21290

CrWMn

5-4

T20250

MnCrWV

5-5

T21347

7CrMn2Mo

5-6

T21355

5Cr8MoVSi

5-7

T21357

7CrSiMnMoV

5-8

T21350

Cr8Mo2SiV

5-9

T21320

Cr4W2MoV

5-10

T21386

6Cr4W3Mo2VNb

Main characteristics and applications With high hardness and wear resistance, small quenching deformation and good hardenability. Suitable for all types of precision measuring tools, prototype, small stamping dies, cold stamping dies, engraving dies, punching dies and structural parts such as lead screw of the lathe. With relatively high hardenability and wear resistance, small quenching deformation and fine and uniformly distributed carbide. Suitable for cold stamping dies whose cross section are not big and with complex deformation. Oil quenched steel with more excess carbide retained than 9SiCr after quenching and low temperature tempering because tungsten will form carbide in the steel,with higher hardness, better wear resistance and good toughness. The steel is very sensitive to carbide network, and in case there is, the blade may have a risk of chipping, consequently, the service life of the tool and die will be decreased. Steels with carbide network must be forged or normalized depending on the severity. Suitable for screw taps, threading tools, reamers and small stamping dies. High carbon low alloy oil quenched steel widely used in the world, with high hardenability, small heat treatment deformation, high hardness and good wear resistance. Suitable for blanking dies for steel sheet and plate, shear knives, punching dies, measuring tools and injection moulds for thermosets. Air quenched steel with small heat treatment deformation. Suitable for trimming dies, plastic moulds, bending tools, blanking dies and precision sizing dies. Modified steel of A8 in ASTM A681, with good hardenability, toughness, and dimensional stability during heat treatment. Suitable for punches and cold forging dies with hardness between HRC55 ～ HRC60, as well as cutting tools for non-metallic materials. Flame hardening steel with wide quenching temperature range and good hardenability, which can be hardened by air cooling, and the hardness can be up toHRC62～HRC64.The quenching process can be managed easily and at low cost. There is small overheat sensitivity and small deformation during air cooling. Suitable for cold bending dies for automobile industry. Steel with high toughness and wear resistance, good hardenability, and dimensional stability during quenching. Suitable for cold shearing dies, trimming dies, curling dies, gauges, wire drawing dies, thread rolling flat dies, and cold stamping dies. Steel with high hardenability, quenching hardness, wear resistance and dimensional stability. Suitable for all types of stamping dies, cold upsetting dies, punching dies, cold extruding diesand thread rolling flat dies. Equivalent to 65Nb. The strength and toughness and manufacturability are improved by adding niobium. Suitable for cold working dies suffering high load such as cold extruding dies, as well as cold stamping and cold upsetting dies for plates, and warm and hot extrusion dies. 59

GB/T XXXX-XXXX

5-11

T21836

6W6Mo5Cr4V

Low carbon high speed steel with lower carbon and vanadium content than W6Mo5Cr4V2, with high toughness. When used as cold work tool steel, mainly used for cold extruding dies for steel and iron materials.

表 C.5（续） 冷作模具用钢的主要特点及用途 序号

统一数字 代号

牌号

5-12

T21830

W6Mo5Cr4V2

5-13

T21209

Cr8

5-14

T21200

Cr12

5-15

T21290

Cr12W

5-16

T21317

7Cr7Mo2V2Si

5-17

T21318

Cr5Mo1V

5-18

T21319

Cr12MoV

5-19

T21310

Cr12Mo1V1

主要特点及用途 Representative grade of tungsten-molybdenum high speed steels, with high toughness, good thermoplasticity and wear resistance, and high red hardness. When used as cold work tool steel, suitable for all types of tools, large cutting tools for plastic thermoforming, as well as wear resistant parts suffering high load such as cold extruding dies and warm extruding dies. Steel with high hardness and wear resistance, and better toughness than Cr12. Suitable for all types of cold work dies where high wear resistance is required. Equivalent to D3 in ASTM A681, with high wear resistance. Suitable for clod stamping dies and punches suffering low shock load and requiring high wear resistance, cold shear knives, drill bushings, gauges and wire drawing dies. Ledeburite steel with high wear resistance and hardenability, but low plasticity and toughness. Suitable for tool and dies requiring high strength and wear resistance and working at tremperature not higher than300℃～400℃, e.g. deep drawing dies for steel sheet and plate, wire drawing dies, thread rolling flat dies, cold stamping dies, shear knives and saw blades. General-purpose steel with higher strength and toughness, better wear resistance than Cr12 and W6Mo5Cr4V2, good cold and hot working properties, and small heat treatment deformation. Suitable for cold extruding dies, cold upsetting dies and cold stamping dies suffering high load. General-purpose air quenched steel with good air quenching ability and high toughness. The wear resistance is between high carbon oil quenched mould steels and high carbon high chromium wear resistant mould steels. Especially suitable for tools and dies where both high wear resistance and high toughness are required, e.g. cropping die for billet shearing, forming dies, rollers, punches, drawing dies and thread rolling dies. Ledeburite steel with high hardenability and wear resistance, small change in size during quenching, more uniformly distributed carbide than Cr12 and high toughness.Suitable for perforating dies with complex configuration, cold shear knives, drawing dies, wire drawing dies, thread rolling flat dies, cold extruding dies and measuring tools. Ledeburite steel with high hardenability, quenching hardness and wear resistance, good anti-oxidation property at high temperature, small deformation during heat treatment. Suitable for high-precision cold working dies, cutting tools and measuring tools with long service life, e.g. piercing dies with complex configuration, cold extruding dies, thread rolling cylindrical dies, thread rolling flat dies, cold shear knives and precision measuring tools.

Table C.6 Main characteristics and applications of hot work tool steels S.N.

Unicode

Steel grade

Main characteristics and applications Steel with similar properties to and slightly lower hardenability than

6-1

T22345

5CrMnMo

5CrNiMo. When working at high temperature, thethermal fatigue resistance is lower than 5CrNiMo. Suitable for all types of forging dies where high strength and high wear resistance are required. 60

GB/T XXXX-XXXX Steel with good toughness, high strength and wear resistance. The hardness 6-2

T22505

5CrNiMo

can be maintained around HBW300 when heated to 500℃. Not sensitive to temper brittleness because of molybdenum. Suitable for large and medium forging dies. Steel with good hardenability, toughness and polishability and can be

6-3

T23504

4CrNi4Mo

hardened by air cooling. Suitable for hot working dies and plastic moulds, as well as some cold working dies. Modified5CrMnMo with high room temperature strength and toughness, good

6-4

T23514

4Cr2NiMoV

temper resistance, hardenability and thermal fatigue resistance. Suitable for hot forging dies.

6-5

6-6

T23515

T23535

6-7

T23208

序号

统一数 字代号

5CrNi2MoV

5Cr2NiMoVSi

8Cr3

Similar to 5CrNiMo, with good hardenability and thermal stability. Suitable for large press forging dies and hot shears. Steel with good hardenability and thermal stability. Suitable for all types of large hot forging dies. Steel with certain room-temperature and high-temperature mechanical properties. Suitable for punches of hot perforating dies, die insert of hot trimming dies, hot upset forging dies, hot bending dies, and components working at temperature lower than 500℃, suffering less shock and requiring wear resistance such as hot shear blades. Also suitable for cold work rolls.

表 C.6（续） 热作模具用钢的主要特点及用途 牌号

6-8

T23274

4Cr5W2VSi

6-9

T23273

3Cr2W8V

6-10

T23352

4Cr5MoSiV

6-11

T23353

4Cr5MoSiV1

主要特点及用途 Die casting die steels with high thermal strength, hardness, wear resistance, toughness and thermal fatigue resistance at medium temperature, and can be hardened by air cooling. Suitable for hot extruding dies and mandrels, die casting dies for light metals such as aluminum and zinc, tools for hot upset forging of alloy structural steels and heat resistant steels, and high-speed hammer forging dies for component forming. Steel with high strength and hardness at high temperature (the hardness is around HBW300 at 650℃), good resistance to cold and hot alternative fatigue, but low toughness. Suitable for punch and die working at high temperature and high stress but not suffering shock load, e.g. the main punch and insert on horizontal forging machine, extruding dies for copper alloy and die casting dies. Also suitable for dies suffering high pressure stress, bending stress and tensile stress at the same time such as backward extrusion dies, and hot metal cutting tools operating under stress at high temperature. Steel with good toughness, thermal strength and thermal fatigue resistance, and can be hardened by air cooling. When air quenched at relatively low austenitizing temperature, the heat treatment deformation is small, there is small tendency to form scales during air quenching and the steel can withstand the erosion of liquid aluminum. Suitable for aluminum die casting dies, hot extruding dies, mandrels and plastic moulds. Die casting die steels equivalent to H13 in ASTM A681, with good toughness, thermal strength, thermal fatigue resistance and certain wear resistance. Can be hardened by air cooling, and the heat treatment deformation is small. Suitable for die casting dies for aluminum, copper and their alloys, hot extruding dies, tools and mandrels for piercing, press forging dies and plastic moulds.

61

GB/T XXXX-XXXX

6-12

T22354

6-13

T23355

6-14

T23364

6-15

T23375

6-16

T23324

6-17

T23323

6-18

T23325

6-19

T23314

6-20

T23313

6-21

T23314

6-22

T23393

Equivalent to H10 in ASTM A681, with excellent hardenability, very high toughness and high-temperature strength. Suitable for hot extruding dies, hot stamping dies, hot forging dies and die casting dies. A kind of die steel can be used both for hot work and cold work, with high thermal strength, high temperature hardness, temper resistance and good wear resistance, thermal fatigue resistance, toughness and thermal plasticity. The dies can work at temperature up to 700℃, and have good resistance to 5Cr4Mo3SiMnVA1 oxidation. When used as hot work tool steel, it has better high temperature strength and thermal fatigue resistance than 3Cr2W8V; when used as cold work tool steel, it has better toughness than Cr12 type steel and low alloy tool steels. Mainly used for hot extruding dies in bearing industry and cold upsetting dies in standard component industry. Low alloy steel used for large section hot forging dies, with good hardenability, high thermal strength, thermal fatigue resistance, wear 4CrMnSiMoV resistance, toughness, temper resistance and cold and hot workability. Mainly used for large hammer forging dies and mechanical forging dies where 5CrNiMo cannot meet the requirement. Steel with good hardenability, toughness, dimensional stability during heat treatment and moderate wear resistance. Suitable for punches with hardness 5Cr5WMoSi between HRC55～HRC60. Also suitable for cold working dies and cutting tools for non-metallic materials. Steel with good toughness and thermal strength, and can be hardened by air cooling, It has small deformation during heat treatment, and there is small 4Cr5MoWVSi tendency to form scales during air quenching. The steel can withstand the erosion of liquid aluminum. Suitable for aluminum die casting dies, press forging dies, hot extruding dies and mandrels for piercing. Modified grade of H10 in ASTM A681, with high strength and toughness, good resistance to cold and hot fatigue and good thermal stability. Suitable for 3Cr3Mo3W2V hot extruding dies, hot stamping dies, hot forging dies and die casting dies. with very high temper resistance and thermal stability, high thermal strength, high-temperature hardness and wear resistance, but lower toughness 5Cr4W5Mo2V and thermal fatigue resistance than 4Cr5MoSiV1. Suitable for hot working dies where high high-temperature strength and wear resistance are required. Can be a substitute for 3Cr2W8V. Modified grade of 4Cr5MoSiV1, with good hardenability, toughness, thermal strength, thermal fatigue resistance and small deformation during heat 4Cr5Mo2V treatment. Suitable for die casting dies for aluminum, copper and their alloys, hot extruding dies, as well as tools and mandrels for piercing. With high thermal strength and toughness, good temper resistance and fatigue 3Cr3Mo3V resistance. Suitable for upsetting dies, hot extruding dies and die casting dies. With good high temperature strength, temper resistance and high thermal 4Cr5Mo3V fatigue resistance. Suitable for hot extruding dies, warm forging dies, die casting dies and thermal forming dies. With high thermal strength, good temper resistance and thermal fatigue 3Cr3Mo3VCo3 resistance. Suitable for hot extruding dies, warm forging dies and die casting dies. 4Cr3Mo3SiV

Table C.7 Main characteristics and applications of plastic mould steels S.N.

7-1

Unicode T10450

Steel grade

SM45

Main characteristics and applications Non-alloy plastic mould steel with good machinability, high quenching hardness, and good strength and toughness and certain wear resistance after QT. Suitable for medium and small plastic dies of medium and low level. 62

GB/T XXXX-XXXX

7-2

T10500

7-3

T10550

7-4

T25303

7-5

T25553

7-6

T25344

7-7

T25378

7-8

T25515

7-9

T25512

7-10

T25572

7-11

T25611

7-12

A64060

7-13

A64000

7-14

S42023

7-15

S42043

Non-alloy plastic mould steel with good machinability but poor weldability and cold deformation property. Suitable for small plastic moulds with SM50 simple configuration or plastic moulds with low requirement on accuracy and service life. Non-alloy plastic mould steel with moderate machinability. Suitable for SM55 small plastic moulds with simple configuration or plastic moulds with low requirement on accuracy and service life. Pre-hardened steel equivalent to P20 in ASTM A681, with good comprehensive 3Cr2Mo properties, high hardenability and uniform hardness even for large section steels, very good polishability, and high surface finish. Pre-hardened steel equivalent to 718 from Sweden ASSAB, with good 3Cr2MnNiMo comprehensive properties, high hardenability and uniform hardness after QT even for large section steels, and very good polishability. Pre-hardened free cutting steel with similar properties to 3Cr2MnNiMo and 4Cr2Mn1MoS better machinability. Pre-hardened free cutting steel suitable for all types of plastic moulds, rubber mould, Clay porcelain mould and perforating mould for printed 8Cr2MnWMoVS board. Also suitable for precision cold stamping dies due to high quenching hardness, good wear resistance, good comprehensive mechanical properties, and small heat treatment deformation. Pre-hardened free cutting steel. By adding sulfur, the machinability of the steel is improved; by adding calcium, the morphology of sulfide, the 5CrNiMnMoVSCa mechanical properties, and the anisotropy of the steel are improved. Suitable for all types of precision injection moulds, compression moulds and rubber moulds. Pre-hardened plastic mould steel with mirror surface. It is a modified grade of 3Cr2MnNiMowith high hardenability, uniform hardness, good 2CrNiMoMnV polishability, EDM performance and texture property. Suitable for nitridingand used for large and medium plastic moulds with mirror surface. Age hardening steel with good comprehensive mechanical properties. The quenching deformation can be avoided because the steel was solution 2CrNi3MoAl treated before machined into moulds. Suitable for complex and precision plastic moulds. Equivalent to 10Ni3MnCuAl, a type of nickel-copper-aluminum age hardening steel with good hardenability, small heat treatment deformation, good 1Ni3MnCuMoAl mirror finishing property. Suitable for plastic moulds with high mirror finish and plastic moulds for household appliance with high requirement on appearance. Low alloy maraging steel, and the name for short is 06Ni. The hardness is between HRC25～HRC28 after solution treatment (can be performed after rough machining). Aging shall be performed after the steel was machined 06Ni6CrMoVTiAl into mould shape and was trimmed and polished by bench worker. The hardness will be increased remarkably and the deformation is small. The mould can be used directly with high accuracy and long service life. Precipitation hardening super high strength steel, and the name for short is 18Ni （ 250 ） , with high strength and toughness, low hardening index, 00Ni18Co8Mo5TiAl good formability and weldability. Suitable for extruding dies and die casting dies for aluminum alloy, precision mould and cold stamping dies. A type of Cr13 corrosion resistant steel, with good machinability, excellent corrosion resistance and high toughness after heat treatment. 2Cr13 suitable for plastic mould operating at high load and with corrosive medium, as well as moulds for transparent plastic products. A type of Cr13 corrosion resistant steel with good mechanical properties, excellent corrosion resistance, polishability and high strength and wear 4Cr13 resistance after heat treatment (quenching and tempering). Suitable for plastic mould operating at high load and with corrosive medium, as well as moulds for transparent plastic products. 63

GB/T XXXX-XXXX

7-16

T25444

序号

统一数 字代号

4Cr13NiVSi

A type of prehardened Cr13 corrosion resistant steel with high hardness after quenching and tempering, superior mirror finishing property, and can be prehardened to hardness of HRC31 ～ HRC35. Suitable for high precision plastic moulds requiring high wear resistance and corrosion resistance, as well as moulds for transparent plastic products.

表 C.7（续） 塑料模具用钢的主要特点及用途 牌号

7-17

T25402

2Cr17Ni2

7-18

T25303

3Cr17Mo

7-19

T25513

3Cr17NiMoV

7-20

S44093

9Cr18

7-21

S46993

9Cr18MoV

主要特点及用途 Prehardened corrosion resistant steel with good polishability. When used as glass mould steel, it has good oxidation resistance. Suitable for corrosion resistant plastic moulds and chromium and nickel coatings can be omitted. A type of prehardened Cr17 corrosion resistant steel with excellent strength and toughness, and high corrosion resistance. Suitable for high precision plastic moulds requiring high wear resistance and corrosion resistance, as well as moulds for transparent plastic products. A type of prehardened Cr17 corrosion resistant steel with excellent strength and toughness, and high corrosion resistance. Suitable for high precision plastic moulds requiring high wear resistance and corrosion resistance, as well as moulds for transparent plastic products. High carbon martensitic steel with very high hardness and wear resistance after quenching, higher corrosion resistance than Cr17-type martensitic steel, and excellent corrosion resistance in atmosphere and water solutions of acids or salts. Suitable for components where wear resistance, high strength and wear resistance are required, e.g. shafts, rods, springs and fasteners. High carbon chromium stainless steel with similar properties and applications to and better thermal strength and temper resistance than 9Cr18, and it is a type of corrosion resistant and wear resistant steel. Suitable for components suffering friction and working with corrosion medium, e.g. measuring tools, blades of stainless slicing machine, shear tools, surgical knife blade and equipment components requiring high wear resistant.

Table C.8 Main characteristics and applications of special-purpose tool steels S.N.

Unicode

Steel grade

Main characteristics and applications High Mn-V nonmagnetic steel, having stable austenite under any status, with rather low permeability, high hardness, strength and good wear

8-1

T26377 7Mn15Cr2Al3V2WMo resistance. Suitable for nonmagnetic moulds, nonmagnetic bearings and structural components that generating no magnetic induction even they

8-2

S31049

2Cr25Ni20Si2

8-3

S51740

0Cr17Ni4Cu4Nb

work in high-intensity magnetic field. Austenite heat resistant steel with good resistance to general corrosion. The maximum service temperature is 1200℃, the maximum continuous service temperature is 1150℃ and the maximum interval service temperature is 1050℃～1100℃. Suitable for heating furnace components and glass moulds. Precipitation hardening martensitic stainless steel with low carbon content, better corrosion resistance and weldability than common martensitic stainless steels, good acid resistance and machinability. The heat treatment process is simple. There is embrittlement tendency when it works at temperature higher than 400℃ for long time. Suitable 64

GB/T XXXX-XXXX

8-4

H21231

8-5

H07718

for components working at temperature lower than 400℃ and requiring acid resistance and high strength. Also suitable for plastic moulds working with corrosive medium and requiring high properties and high precision. Fe-25Ni-15Cr based age-hardening super alloy, equivalent to GH2132B. The properties of the steel have been comprehensively strengthened by adding molybdenum, titanium, aluminum, vanadium and minute amount of boron. It has high wear resistance, anti-deformability property and oxidation Ni25Cr15Ti2MoMn resistance at high temperature, and good thermal fatigue resistance, and it has no notch sensitivity. Suitable for load-bearing parts working at temperature lower than 650℃ for long time, and hot working dies such as copper busbar extruding dies, hot extruding dies and inner cylinder. Equivalent to In718 alloy, a type of precipitation hardening nickel based super alloy with BCT γ″ phase and FCC γ′ phase. The alloy was precipitation strengthened by γ′(Ni3AlTi) phase by adding aluminum and titanium into the alloy to form intermetallic compound. It has good high Ni53Cr19Mo3TiNb temperature strength, high temperature stability, good oxidation resistance, excellent cold and hot fatigue resistance and impact toughness. Suitable for hot forging dies, punches, hot extruding dies and die casting dies that work at temperature higher than 600℃.

65

GB/T XXXX-XXXX Annex D (Informative) Cross-references of Chinese tool steel designations to designations in other national systems

Table D.1 is the cross-references of Chinese tool steel designations to designations in other national systems

Table D.1 Cross-references of steel designations in this standard to designations in ASTM, JIS and ISO standard Steel type Non-alloy steels for cutting tools and moulds

steels for measuring tools and cutting tools

Shockresisting tool steels

Steels for rollers

Cold work tool steels

1-1 1-2 1-3 1-4 1-5 1-6 1-7 1-8 2-1 2-2 2-3 2-4 2-5 2-6

Steel grade of this standard T7 T8 T8Mn T9 T10 T11 T12 T13 9SiCr 8MnSi Cr06 Cr2 9Cr2 W

ASTM A 686/ASTM A681 — — W1-8 W1-8 1/2 W1-10 W1-11 W1-11 1/2 — — — — L3 — F1

JIS G4401/JIS G4404 SK70 SK80 SK85 SK90 SK105 — SK120 — — — SKS8 — — SKS2

3-1

4CrW2Si

—

SKS41

—

3-2

5CrW2Si

S1

—

—

3-3

6CrW2Si

—

—

—

3-4

6CrMnSi2Mo1V

S5

—

—

3-5

5Cr3MnSiMo1V

S7

—

—

3-6

6CrW2SiV

—

—

60WCrV8

4-1

9Cr2V

—

—

—

4-2

9Cr2Mo

—

—

—

4-3

9Cr2MoV

—

—

—

4-4

8Cr3NiMoV

—

—

—

4-5 5-1 5-2 5-3 5-4 5-5 5-6 5-7

9Cr5NiMoV 9Mn2V 9CrWMn CrWMn MnCrWV 7CrMn2Mo 5Cr8MoVSi 7CrSiMnMoV

— O2 O1 — — — — —

— — SKS3 SKS31 — — — —

— — 95MnCr5 — 95MnWCr5 70MnMoCr8 — —

S.N.

ISO 4957 C70U C80U — C90U C105U — C120U — — — — — — —

66

GB/T XXXX-XXXX

表 D.1（续） 本标准牌号同ASTM、JIS、ISO标准牌号对照表 Steel type

S.N.

Cold work tool steels

Hot work tool steels

Plastic mould steels

5-8 5-9 5-10 5-11 5-12 5-13 5-14 5-15 5-16 5-17 5-18 5-19

Steel grade of this standard Cr8Mo2VSi Cr4W2MoV 6Cr4W3Mo2VNb 6W6Mo5Cr4V W6Mo5Cr4V2 Cr8 Cr12 Cr12W 7Cr7Mo2V2Si Cr5Mo1V Cr12MoV Cr12Mo1V1

ASTM A 686/ASTM A681 — — — — — — D3 — — A2 — D2

JIS G4401/JIS G4404 — — — — — — SKD1 SKD2 — SKD12 — SKD10

— — — — — — X210Cr12 X210CrW12 — X100CrMoV5 — X153CrMoV12

6-1

5CrMnMo

—

—

—

6-2

5CrNiMo

L6

—

—

6-3

4CrNi4Mo

—

SKT6

45CrNiMo16

6-4

4Cr2NiMoV

—

—

—

6-5

5CrNi2MoV

—

SKT4

55NiCrMoV7

6-6 6-7 6-8 6-9 6-10 6-11 6-12 6-13 6-14 6-15 6-16 6-17 6-18 6-19 6-20 6-21 6-22 7-1 7-2 7-3 7-4 7-5 7-6

5Cr2NiMoVSi 8Cr3 4Cr5W2VSi 3Cr2W8V 4Cr5MoSiV 4Cr5MoSiV1 4Cr3Mo3SiV 5Cr4Mo3SiMnVA1 4CrMnSiMoV 5Cr5WMoSi 4Cr5MoWVSi 3Cr3Mo3W2V 5Cr4W5Mo2V 4Cr5Mo2V 3Cr3Mo3V 4Cr5Mo3V 3Cr3Mo3VCo3 SM45 SM50 SM55 3Cr2Mo 3Cr2MnNiMo 4Cr2Mn1MoS

— — — H21 H11 H13 H10 — — A8 H12 — — — — — — — — — P20 — —

— — — SKD5 SKD6 SKD61 — — — — — — — — SKD7 — — — — — — — —

— — — X30WCrV9-3 X37CrMoV5-1 X40CrMoV5-1 — — — — X35CrWMoV5 — — — 32CrMoV12-28 — — C45U — — 35CrMo7 40CrMnNiMo8-6-4 —

ISO 4957

表 D.1（续） 本标准牌号同ASTM、JIS、ISO标准牌号对照表 Steel type Plastic mould

S.N. 7-7 7-8

Steel grade of this standard 8Cr2MnWMoVS 5CrNiMnMoVSCa

ASTM A 686/ASTM A681 — —

JIS G4401/JIS G4404 — —

ISO 4957 — — 67

GB/T XXXX-XXXX steels

specialpurpose tool steels

7-9 7-10 7-11 7-12 7-13 7-14 7-15 7-16 7-17 7-18 7-19 7-20 7-21

2CrNiMoMnV 2CrNi3MoAl 1Ni3MnCuAl 06Ni6CrMoVTiAl 00Ni18Co8Mo5TiAl 2Cr13 4Cr13 4Cr13NiVSi 2Cr17Ni2 3Cr17Mo 3Cr17NiMoV 9Cr18 9Cr18MoV

— — — — — — — — — — — — —

— — — — — — — — — — — — —

— — — — — — — — — X38CrMo16 — — —

8-1

7Mn15Cr2Al3V2Mo

—

—

—

8-2

2Cr25Ni20Si2

—

—

—

8-3

0Cr17Ni4Cu4Nb

—

—

—

8-4

Ni25Cr15Ti2MoMn

—

—

—

8-5

Ni53Cr19Mo3TiNb

—

—

—

68