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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:

SECTIONScope1Scope Description1.1A Reference Document1.2Acceptance Standards for Parts not Covered1.3Magnetic Particle Method Techniques1.4Personnel Qualifications1.5Nondestructive Testing Agency1.6Table of Contents1.7SI Units1.8Safety Caveat1.9Referenced Documents2ASTM Standards2.1SAE Documents2.2ASNT Documents2.3U.S. Government Documents2.4Definitions3Summary of Guide4Principle4.1Method4.2Magnetization4.3Types of Magnetic Particle and Their Use4.4Evaluation of Indications4.5Typical Magnetic Particle Indications4.6Significance and Use5Equipment6Types6.1 SECTIONPortability6.2Yokes6.3Prods6.4Black Light6.5Equipment Verification6.6Examination Area7Light Intensity for Examination7.1Housekeeping7.2Magnetic Particle Materials8Particle Types8.2Particle Characteristics8.3Dry Particles8.4Wet Particle Systems8.5Part Preparation9General9.1Cleaning Examination Surface9.2Sequence of Operations10Sequencing Particle Application and Establishing Magnetic Flux Field10.1Types of Magnetizing Currents11Basic Current Types11.1Part Magnetization Techniques12Examination Coverage12.1Direct and Indirect Magnetization12.2Choosing a Magnetization Technique12.3Direction of Magnetic Fields13Discontinuity Orientation vs Magnetic Field Direction13.1Circular Magnetization13.2Torodial Magnetization13.3Longitudinal Magnetization13.4Multidirectional Magnetization13.5Magnetic Field Strength14Magnetizing Field Strengths14.1Establishing Field Strengths14.2Guidelines for Establishing Magnetic Fields14.3Application of Dry and Wet Magnetic Particles15Dry Magnetic Particles15.1Wet Particles Applications15.2Magnetic Slurry/Paint15.3Magnetic Polymers15.4Interpretation of Indications16Valid Indications16.1Recording of Indications17Means of Recording17.1Accompanying Information17.2Demagnetization18Applicability18.1Demagnetization Methods18.2Extent of Demagnetization18.3Post Examination Cleaning19Particle Removal19.1Means of Particle Removal19.2Evaluation of System Performance/Sensitivity20Contributor Factors20.1Maintenance and Calibration of Equipment20.2Equipment Checks20.3Examination Area Light Level Control20.4Dry Particle Quality Control Tests20.5Wet Particle Quality Control Tests20.6Bath Characteristics Control20.7Verifying System Performance20.8Procedure and Report21Written Procedure21.1Written Reports21.2Acceptance Standards22Safety23 SECTIONPrecision and Bias24Keywords25AnnexAnnexA1Appendix X1.AppendixX1Appendix X2.AppendixX2

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.