ASTM-E709 Standard Guide for Magnetic Particle Testing

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Standard Guide for Magnetic Particle Testing



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1.1 This guide describes techniques for both dry and wet magnetic particle examination, a nondestructive method for detecting cracks and other discontinuities at or near the surface in ferromagnetic materials. Magnetic particle examination may be applied to raw material, semifinished material (billets, blooms, castings, and forgings), finished material and welds, regardless of heat treatment or lack thereof. It is useful for preventive maintenance examination.

1.1.1 This guide is intended as a reference to aid in the preparation of specifications/standards, procedures and techniques.

1.2 This guide is also a reference that may be used as follows:

1.2.1 To establish a means by which magnetic particle examination, procedures recommended or required by individual organizations, can be reviewed to evaluate their applicability and completeness.

1.2.2 To aid in the organization of the facilities and personnel concerned in magnetic particle examination.

1.2.3 To aid in the preparation of procedures dealing with the examination of materials and parts. This guide describes magnetic particle examination techniques that are recommended for a great variety of sizes and shapes of ferromagnetic materials and widely varying examination requirements. Since there are many acceptable differences in both procedure and technique, the explicit requirements should be covered by a written procedure (see Section 21 ).

1.3 This guide does not indicate, suggest, or specify acceptance standards for parts/pieces examined by these techniques. It should be pointed out, however, that after indications have been produced, they must be interpreted or classified and then evaluated. For this purpose there should be a separate code, specification, or a specific agreement to define the type, size, location, degree of alignment and spacing, area concentration, and orientation of indications that are unacceptable in a specific part versus those which need not be removed before part acceptance. Conditions where rework or repair are not permitted should be specified.

1.4 This guide describes the use of the following magnetic particle method techniques.

1.4.1 Dry magnetic powder (see 8.4 ),

1.4.2 Wet magnetic particle (see 8.5),

1.4.3 Magnetic slurry/paint magnetic particle (see 8.5.8 ), and

1.4.4 Polymer magnetic particle (see 8.5.8).

1.5 Personnel Qualification—Personnel performing examinations in accordance with this guide shall be qualified and certified in accordance with ASNT Recommended Practice No. SNT-TC-1A, ANSI/ASNT Standard CP-189, NAS 410, or as specified in the contract or purchase order.

1.6 Nondestructive Testing Agency— If a nondestructive testing agency as described in Practice E 543 is used to perform the examination, the testing agency shall meet the requirements of Practice E 543.

1.7 Table of Contents:

Scope Description1.1
A Reference Document1.2
Acceptance Standards for Parts not Covered1.3
Magnetic Particle Method Techniques1.4
Personnel Qualifications1.5
Nondestructive Testing Agency1.6
Table of Contents1.7
SI Units1.8
Safety Caveat1.9
Referenced Documents2
ASTM Standards2.1
SAE Documents2.2
ASNT Documents2.3
U.S. Government Documents2.4
Summary of Guide4
Types of Magnetic Particle and Their Use4.4
Evaluation of Indications4.5
Typical Magnetic Particle Indications4.6
Significance and Use5
Black Light6.5
Equipment Verification6.6
Examination Area7
Light Intensity for Examination7.1
Magnetic Particle Materials8
Particle Types8.2
Particle Characteristics8.3
Dry Particles8.4
Wet Particle Systems8.5
Part Preparation9
Cleaning Examination Surface9.2
Sequence of Operations10
Sequencing Particle Application and Establishing Magnetic Flux Field10.1
Types of Magnetizing Currents11
Basic Current Types11.1
Part Magnetization Techniques12
Examination Coverage12.1
Direct and Indirect Magnetization12.2
Choosing a Magnetization Technique12.3
Direction of Magnetic Fields13
Discontinuity Orientation vs Magnetic Field Direction13.1
Circular Magnetization13.2
Torodial Magnetization13.3
Longitudinal Magnetization13.4
Multidirectional Magnetization13.5
Magnetic Field Strength14
Magnetizing Field Strengths14.1
Establishing Field Strengths14.2
Guidelines for Establishing Magnetic Fields14.3
Application of Dry and Wet Magnetic Particles15
Dry Magnetic Particles15.1
Wet Particles Applications15.2
Magnetic Slurry/Paint15.3
Magnetic Polymers15.4
Interpretation of Indications16
Valid Indications16.1
Recording of Indications17
Means of Recording17.1
Accompanying Information17.2
Demagnetization Methods18.2
Extent of Demagnetization18.3
Post Examination Cleaning19
Particle Removal19.1
Means of Particle Removal19.2
Evaluation of System Performance/Sensitivity20
Contributor Factors20.1
Maintenance and Calibration of Equipment20.2
Equipment Checks20.3
Examination Area Light Level Control20.4
Dry Particle Quality Control Tests20.5
Wet Particle Quality Control Tests20.6
Bath Characteristics Control20.7
Verifying System Performance20.8
Procedure and Report21
Written Procedure21.1
Written Reports21.2
Acceptance Standards22
Precision and Bias24
Appendix X1.Appendix
Appendix X2.Appendix

1.8 The numerical values shown in inch-pound units are to be regarded as the standard. SI units are provided for information only.

1.9 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.


dye; evaluation; examination; fluorescent; inspection; magnetic particle; nondestructive; testing; ICS Number Code 77.040.20 (Non-destructive testing of metals)

To find similar documents by ASTM Volume:

03.03 (Nondestructive Testing)

To find similar documents by classification:

77.040.20 (Non-destructive testing of metals Non-destructive testing in general, see 19.100 Non-destructive testing of welded joints, see 25.160.40)

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Publication Date

July 14, 2021

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Page Count

48 pages

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