Pci-Pr-64-08 Procedure Magnetic Particle Examination [PDF]

Zitiervorschau

MAGNETIC PARTICLE TESTING PROCEDURE

PCI-PR-64

TABLE OF CONTENTS 1. SCOPE ............................................................................................................................... 3 2. REFERENCES ...................................................................................................................... 3 3. PERSONNEL ....................................................................................................................... 3 AJOUTER LA PARTIE ''RESPONSABILITIES'' 4. MAGNETIZING TECHNIQUES ............................................................................................. 3 5. CONSUMABLES ................................................................................................................. 3 5.1. Contrast paints ............................................................................................................... 3 5.2. Inks and powders ............................................................................................................ 3 6. VIEWING CONDITIONS...................................................................................................... 4 7. SAFETY PRECAUTIONS ...................................................................................................... 4 8. METHODOLOGY................................................................................................................ 4 8.1. Techniques .................................................................................................................... 4 8.2. Equipment ..................................................................................................................... 4 8.3. Temperature limitation .................................................................................................... 5 8.4. Surface condition ............................................................................................................ 5 8.5. Background paint ............................................................................................................ 5 8.6. Sensitivity ...................................................................................................................... 5 8.7. Sequence of operation ..................................................................................................... 6 8.8. Non relevant indications................................................................................................... 6 8.9. De-magnetizing ............................................................................................................... 6 8.10. Marking of flaw indications ............................................................................................. 6 9. INTERPRETATION OF RESULTS .......................................................................................... 6 10. ACCEPTANCE CRITERIA ................................................................................................... 7 11. RECORDS ......................................................................................................................... 8

This document is the property of BECA; no part of it shall be reproduced or transmitted without prior written BECA’s authorization.

PCI-PR-64/08

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MAGNETIC PARTICLE TESTING PROCEDURE

PCI-PR-64

1. SCOPE This document provides the procedure to be employed for the magnetic particle examination of ferromagnetic welds and adjacent base materials using either magnetic or current flow technique. It is intended for use on work governed by the codes listed in paragraph 2.0 of this procedure

2. REFERENCES 

AWS D1.1: Structural steel welding code



ASME Section V, Non destructive examination code, Article 7



Standard Practice for Magnetic particle Inspection Method, ASTM E-709

3. PERSONNEL Personnel having II level according to ASNT SNT-TC-1A or equivalent are authorized to perform Magnetic particle Testing.

4. MAGNETIZING TECHNIQUES

RESPONSABILITIES

The equipment provided by the company for use in the performance of magnetic particle testing shall normally be of the portable tube. Magnetic fields shall be induced into materials under test by one of the following methods: 

Magnetic flow technique



Current flow technique

Only calibrated equipments shall be used and calibration certificate shall be submitted for review and approval.

5. CONSUMABLES 5.1. Contrast paints The ability to see indication on the contrast between the color of ink and the back and background. To improve the efficiency of the process the specimen shall be given a preliminary coat of white paint to present a high contrast background to the black magnetic ink delineating the indication. The contrast paint shall be a type which is quickly drying and can be applied to give a thin even coat. Proprietary brand of paint shall be used whenever possible.

5.2. Inks and powders The concentration of all inks and powders, provided by the company, for the proposes of magnetic particle inspection shall meet the requirements of several norm below. Inks and powders shall be supplied by recognized agents. The preferred and any alternative brand will be stipulated on the appropriate technique sheet. Consumable materials shall be supported by data sheet & validity certificates.

This document is the property of BECA; no part of it shall be reproduced or transmitted without prior written BECA’s authorization.

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MAGNETIC PARTICLE TESTING PROCEDURE

PCI-PR-64

6. VIEWING CONDITIONS The area to be inspected shall be evenly illuminated by daylight or artificial light. The level of the intensity of the light shall not be less than 1000lux. This can be achieved by using a tungsten filament lamp of 100 watts of a distance of approximately 0.2m.

7. SAFETY PRECAUTIONS In accordance with the control of substances hazardous to health (COSHH) all technicians employed to carry out magnetic particle testing shall have access to and shall be familiar with data sheet that fully describe the nature of the hazard associated with the flammability and toxicity of solvent based materials. 8. METHODOLOGY

8.1. Techniques For all magnetic particle inspection performed by the company a technique sheet shall supplement this procedure. The technique sheet shall define the parameters that govern the test and shall stipulate the acceptance criteria. The company’s standard technique sheet is shown.

8.2. Equipment 8.2.1. Magnetic flow Where the component or item being tested closes the magnetizing circuit of an electromagnet or permanent magnet.

8.2.1.1. Magnetizing Yokes (AC electromagnet) This method shall be the proffered method where the use of portable hand magnets is required. All Yokes shall be supplied with articulated pole pieces that can provide intimate contact with the surface of the item or component being tested. The magnetizing force of each yoke shall be demonstrated by determining the minimum lifting power that shall exceed 4.5 kg at the maximum pole spacing at which full surface contact can be made with the test load. Each yoke shall be uniquely identified. The function testing of magnetic yokes shall be carried out before use or daily if the magnet is in constant use. The function test shall be carried out by lifting a suitable test weight with the yoke. The acceptable performance of the function test shall be recorded on the record sheet. Any yoke that can not lift the test weight shall be immediately withdrawn from service. The function test of electromagnets shall also include visual inspection of the articulated joints to ensure a free movement according to the original design of the magnet.

8.2.1.2. Permanent magnetic The use of permanent magnet shall not be normally preferred to the use of AC yokes. However, in certain operating condition the use of the electromagnets may prove impracticable. The magnetizing force of permanent magnets shall be demonstrated by determining their minimum lifting power. Permanent magnets shall be able to lift by magnetic attraction alone 18 kg. Additionally such magnets shall exhibit a pull-off force (the force needed to be applied to one pole piece to break down its adhesion to the test surface) of at least 9kg. This shall be carried out using a spring balance of the plate. The ability of the magnet to meet this requirement shall be demonstrated immediately before use. The successful completion of the lifting test shall be recorded on the format given.

This document is the property of BECA; no part of it shall be reproduced or transmitted without prior written BECA’s authorization.

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MAGNETIC PARTICLE TESTING PROCEDURE

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8.2.2. Test weights Test weights shall be uniquely identified and certified to provide objective evidence of their true weights

8.2.3. Current flow When current form external power source passes between two contacts, generally affected by the means of hand help probes. This method shall be used for the inspection of large areas and welds. The equipment shall only be used together with a specific techniques provided by the company and approved by its client. The technique sheet shall specify the equipment type and current values according to approved inspection codes.

8.3. Temperature limitation 8.3.1. Wet magnetic particle examination The magnetic particle examination shall be the preferred method and shall be carried out in all instances unless the surface temperature of the object being tested exceeds 57°C.

8.3.2. Dry powder particle examination The dry powder method of inspection shall be used in all cases where surface temperatures of the item being tested exceed 57°C. The selection of the type of powder shall depend of the surface temperature of the item to be examined and shall normally be defined by the maximum working temperature of the powder as described by the manufacture of the powder.

8.4. Surface condition Visual inspection shall be carried out before commencement of magnetic particle inspection. The technician performing magnetic particle inspection shall ensure that the surfaces to be inspected are free from all extraneous matter such us paint, grease, weld spatter and accumulation of dust, dirt or water. The surface of the test area shall be free from rust. During the testing of welds or other areas that have been mechanically worked or finished the technician shall make special notice of grinding marks or any abrupt changes of shape or section that may complicate the interpretation of inspection results.

8.5. Background paint The application of the contrast paint shall be made on the surface that is grease free. If the paint shows sings of lifting due to traces of oil, this shall be overcome by rubbing the first coat into the surface with a dry cloth and than applied the second coat.

8.6. Sensitivity Adequate sensitivity shall be demonstrated by using magnetic flux indicators of type either a, b or c below: a) Burmah Castrol Strips Type 1 Brass Finish b) Berthold Penetrameter used at setting number 2 c) Burmah Castrol Strips Type 2 Silver Finish Magnetic flux indicator shall not be employed when permanent magnets are used to induce the magnetic field.

This document is the property of BECA; no part of it shall be reproduced or transmitted without prior written BECA’s authorization.

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MAGNETIC PARTICLE TESTING PROCEDURE

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With the indicators fixed or held in position on the surface being tested the magnetizing field shall be applied across the axis of the indicator with indicator positioned centrally between the poles of the magnet. After allowing five seconds for particle migration, with magnetic filed applied, the indicator should show a clearly defined congregation of magnetic particles indication the artificial defect. For a satisfactory indication the artificial defect. For a satisfactory indication the test shall be repeated with the magnetizing force applied at 90° to the axis of indicator.

8.7. Sequence of operation 

All surfaces shall be visually inspected (before commencement of testing) to ensure that they are free from any foreign material such as grease, paint etc.



If required white background paint shall be applied to the test surface.



The magnetizing field shall then be applied to the test area.



The magnetic ink or powder shall be sprayed onto the area being tested wile the magnetic field is applied.



The surface being tested shall be visually inspected during the time that magnetizing force is applied in two perpendicular directions at least



The position of any defect indications seen shall be identified compared with a datum point marked on the test piece.



The magnetic field shall be withdrawn.



Post inspection cleaning shall normally be associated with magnetic particle inspection to remove the residue of testing. Due to other consideration, i.e. contractual responsibilities, the permanent protection of structural and piping systems, detailed method of cleaning are considered outside the scope of this procedure. However, all technicians are instructed to ensure that acceptable standards of housekeeping are maintained.



An inspection report shall than be compiled and submitted.

8.8. Non relevant indications Any indication believed to be non-relevant, such as grinding marks that may cause indications shall be regarded as unacceptable until the indication has been eliminated by surface conditioning or by further satisfactory evaluation.

8.9. De-magnetizing If required

8.10. Marking of flaw indications The marking of flaw indications on the tested component shall be considered necessary as the resultant indication found at the time of inspection can not be considered permanent. The position of flows shall be marked on the tested component by a method that will not affect the use of the component or prejudice any subsequent testing Magnetizing units for electromagnetic yokes shall be capable of producing alternating current, direct current, or both. This procedure is also applicable for permanent magnetizing technique

This document is the property of BECA; no part of it shall be reproduced or transmitted without prior written BECA’s authorization.

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MAGNETIC PARTICLE TESTING PROCEDURE

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9. INTERPRETATION OF RESULTS Adequate illumination shall be provided to ensure proper evaluation. Indications will be revealed by retention of the magnetic particles. All indications are not necessarily defects however, since excessive surface roughness and magnetic permeability variations (such as at the edge of heat affected zones) may produce similar indications which are not relevant. Defective conditions are actual or real openings in the surfaces of the material such as cracks, laps, porosity, incomplete fusion… etc, any interruption in the normal physical structure of the material (weld or base metal) which will cause detectable magnetic particle indications.

10. ACCEPTANCE CRITERIA -ASME AWS D1.1 The acceptance criteria are evaluated in accordance with the attached table here below for visual inspection:

Acceptance criteria are based on AWS D1.1 : 2010 Table 6.1

This document is the property of BECA; no part of it shall be reproduced or transmitted without prior written BECA’s authorization.

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MAGNETIC PARTICLE TESTING PROCEDURE

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A REMPLACER INTEGRALEMENT PAR LE TABLEAU 6.1 DE L'AWS D1.1 : 2010 11. RECORDS For each examination, the following information shall be recorded: (a) procedure identification and revision (b) magnetic particle equipment and type of current (c) magnetic particles (visible or fluorescent, wet or dry) (d) examination personnel identity and if required by referencing Code Section, qualification level (e) map or record of indications per ASMEV -T-792 (f) material and thickness (g) lighting equipment (h) date of examination

This document is the property of BECA; no part of it shall be reproduced or transmitted without prior written BECA’s authorization.

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