1、Designation: E709 15Standard Guide forMagnetic Particle Testing1This standard is issued under the fixed designation E709; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A number in parentheses indicates
2、the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.This standard has been approved for use by agencies of the U.S. Department of Defense.1. Scope*1.1 This guide2covers techniques for both dry and wetmagnetic particle testing, a no
3、ndestructive method for detect-ing cracks and other discontinuities at or near the surface inferromagnetic materials. Magnetic particle testing may beapplied to raw material, semifinished material (billets, blooms,castings, and forgings), finished material and welds, regardlessof heat treatment or l
4、ack thereof. It is useful for preventivemaintenance testing.1.1.1 This guide is intended as a reference to aid in thepreparation of specifications/standards, procedures and tech-niques.1.2 This guide is also a reference that may be used asfollows:1.2.1 To establish a means by which magnetic particle
5、testing, procedures recommended or required by individualorganizations, can be reviewed to evaluate their applicabilityand completeness.1.2.2 To aid in the organization of the facilities and person-nel concerned in magnetic particle testing.1.2.3 To aid in the preparation of procedures dealing witht
6、he examination of materials and parts. This guide describesmagnetic particle testing techniques that are recommended fora great variety of sizes and shapes of ferromagnetic materialsand widely varying examination requirements. Since there aremany acceptable differences in both procedure and techniqu
7、e,the explicit requirements should be covered by a writtenprocedure (see Section 21).1.3 This guide does not indicate, suggest, or specify accep-tance standards for parts/pieces examined by these techniques.It should be pointed out, however, that after indications havebeen produced, they must be int
8、erpreted or classified and thenevaluated. 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 specificpart versus those
9、 which need not be removed before partacceptance. Conditions where rework or repair is not permittedshould be specified.1.4 This guide describes the use of the following magneticparticle 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
10、/paint magnetic particle (see 8.5.7),and1.4.4 Polymer magnetic particle (see 8.5.8).1.5 Personnel QualificationPersonnel performing exami-nations in accordance with this guide should be qualified andcertified in accordance withASNT Recommended Practice No.SNT-TC-1A, ANSI/ASNT Standard CP-189, NAS 41
11、0, or asspecified in the contract or purchase order.1.6 Nondestructive Testing AgencyIf a nondestructivetesting agency as described in Practice E543 is used to performthe examination, the nondestructive testing agency should meetthe requirements of Practice E543.1.7 The values stated in inch-pound u
12、nits are to be regardedas standard. The values given in parentheses are mathematicalconversions to SI units that are provided for information onlyand are not considered standard.1.8 Warning: Mercury has been designated by many regu-latory agencies as a hazardous material that can cause seriousmedica
13、l issues. Mercury, or its vapor, has been demonstratedto be hazardous to health and corrosive to materials. Cautionshould be taken when handling mercury and mercury contain-ing products. See the applicable product Safety Data Sheet(SDS) for additional information. Users should be aware thatselling m
14、ercury and/or mercury containing products into yourstate or country may be prohibited by law.1.9 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the user of this standard to establish appro-priate safety and health prac
15、tices and determine the applica-bility of regulatory limitations prior to use.1This guide is under the jurisdiction of ASTM Committee E07 on Nondestruc-tive Testing and is the direct responsibility of Subcommittee E07.03 on LiquidPenetrant and Magnetic Particle Methods.Current edition approved June
16、1, 2015. Published June 2015. Originallyapproved in 1980. Last previous edition approved in 2014 as E709 - 14. DOI:10.1520/E0709-15.2For ASME Boiler and Pressure Vessel Code Applications see related GuideSE-709 in Section II of that Code.*A Summary of Changes section appears at the end of this stand
17、ardCopyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States12. Referenced Documents2.1 ASTM Standards:3D93 Test Methods for Flash Point by Pensky-MartensClosed Cup TesterD445 Test Method for Kinematic Viscosity of Transparentand Opaque Liquids
18、 (and Calculation of Dynamic Viscos-ity)E165/E165M Practice for Liquid Penetrant Examination forGeneral IndustryE543 Specification for Agencies Performing NondestructiveTestingE1316 Terminology for Nondestructive ExaminationsE1444/E1444M Practice for Magnetic Particle Testing2.2 Society of Automotiv
19、e Engineers (SAE): Aerospace Ma-terials Specifications:4AMS 2300 Premium Aircraft Quality Steel CleanlinessMagnetic Particle Inspection ProcedureAMS 2301 Aircraft Quality Steel Cleanliness Magnetic Par-ticle Inspection ProcedureAMS 2303 Aircraft Quality Steel Cleanliness MartensiticCorrosion Resista
20、nt Steels Magnetic Particle InspectionProcedureAMS 2641 Vehicle Magnetic Particle InspectionAMS 3040 Magnetic Particles, Non-fluorescent, DryMethodAMS 3041 Magnetic Particles, Non-fluorescent, WetMethod, Oil Vehicle, Ready to UseAMS 3042 Magnetic Particles, Non-fluorescent, WetMethod, Dry PowderAMS
21、3043 Magnetic Particles, Non-fluorescent, Oil Vehicle,Aerosol PackagedAMS 3044 Magnetic Particles, Fluorescent, Wet Method,Dry PowderAMS 3045 Magnetic Particles, Non-fluorescent, WetMethod, Oil Vehicle, Ready to UseAMS 3046 Magnetic Particles, Non-fluorescent, WetMethod, Oil Vehicle, Aerosol Package
22、dAMS 5062 Steel, Low Carbon Bars, Forgings, Tubing,Sheet, Strip, and Plate 0.25 Carbon, MaximumAMS 5355 Investment CastingsAMS-I-83387 Inspection Process, Magnetic RubberAS 4792 Water Conditioning Agents for Aqueous MagneticParticle InspectionAS 5282 Tool Steel Ring Standard for Magnetic ParticleIns
23、pectionAS 5371 Reference Standards Notched Shims for MagneticParticle Inspection2.3 American Society for Nondestructive Testing:5SNT-TC-1A Personnel Qualification and Certification inNondestructive TestingCP-189 ASNT Qualification and Certification of Nonde-structive Testing Personnel2.4 Federal Sta
24、ndards:6A-A-59230 Fluid, Magnetic Particle Inspection, SuspensionFED-STD 313 Material Safety Data Sheets Preparation andthe Submission of2.5 OSHA Document:729CFR 1910.1200 Hazard Communication2.6 AIA Documents:8NAS 410 Nondestructive Testing Personnel Qualificationand Certification3. Terminology3.1
25、For definitions of terms used in the practice, refer toTerminology E1316.4. Summary of Guide4.1 PrincipleThe magnetic particle method is based onestablishing a magnetic field with high flux density in aferromagnetic material. The flux lines must spread out whenthey pass through non-ferromagnetic mat
26、erial such as air in adiscontinuity or an inclusion. Because flux lines can not cross,this spreading action may force some of the flux lines out of thematerial (flux leakage). Flux leakage is also caused by reduc-tion in ferromagnetic material (cross-sectional change), a sharpdimensional change, or
27、the end of the part. If the flux leakageis strong enough, fine magnetic particles will be held in placeand an accumulation of particles will be visible under theproper lighting conditions. While there are variations in themagnetic particle method, they all are dependent on thisprinciple, that magnet
28、ic particles will be retained at thelocations of magnetic flux leakage. The amount of flux leakageat discontinuities depends primarily on the following factors:flux density in the material, and size, orientation, and proximityto the surface of a discontinuity. With longitudinal fields, all ofthe flu
29、x lines must complete their loops though air and anexcessively strong magnetic field may interfere with examina-tion near the flux entry and exit points due to the highflux-density present at these points.4.2 MethodWhile this practice permits and describesmany variables in equipment, materials, and
30、procedures, thereare three steps essential to the method:4.2.1 The part must be magnetized.4.2.2 Magnetic particles of the type designated in thecontract/purchase order/specification should be applied whilethe part is magnetized or immediately thereafter.4.2.3 Any accumulation of magnetic particles
31、must beobserved, interpreted, and evaluated.4.3 Magnetization:3For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website
32、.4Available from Society of Automotive Engineers (SAE), 400 CommonwealthDr., Warrendale, PA 15096-0001, http:/www.sae.org.5Available fromAmerican Society for NondestructiveTesting (ASNT), P.O. Box28518, 1711 Arlingate Ln., Columbus, OH 43228-0518, http:/www.asnt.org.6Available from Standardization D
33、ocuments Order Desk, DODSSP, Bldg. 4,Section D, 700 Robbins Ave., Philadelphia, PA 19111-5098, http:/www.dodssp.daps.mil.7Available from Occupational Safety and Health Administration (OSHA), 200Constitution Ave., NW, Washington, DC 20210, http:/www.osha.gov.8Available from Aerospace Industries Assoc
34、iation of America, Inc. (AIA), 1000Wilson Blvd., Suite 1700,Arlington, VA22209-3928, http:/www.aia-aerospace.org.E709 1524.3.1 Ways to MagnetizeA ferromagnetic material can bemagnetized either by passing an electric current through thematerial or by placing the material within a magnetic fieldorigin
35、ated by an external source. The entire mass or a portionof the mass can be magnetized as dictated by size andequipment capacity or need.As previously noted, in order to bedetectable, the discontinuity must interrupt the normal path ofthe magnetic field lines. If a discontinuity is open to thesurface
36、, the flux leakage attracting the particles will be at themaximum value for that particular discontinuity. When thatsame discontinuity is below the surface, flux leakage evidenton the surface will be a lesser value.4.3.2 Field DirectionIf a discontinuity is oriented parallelto the magnetic field lin
37、es, it may be essentially undetectable.Therefore, since discontinuities may occur in any orientation, itmay be necessary to magnetize the part or the area of interesttwice or more sequentially in different directions by the samemethod or a combination of different methods (see Section 13)to induce m
38、agnetic field lines in a suitable direction in whichto perform an adequate examination.4.3.3 Field StrengthThe magnetic field must be of suffi-cient strength to indicate those discontinuities which areunacceptable, yet must not be so strong that an excess of localparticle accumulation masks relevant
39、 indications (see Section14).4.4 Types of Magnetic Particles and Their UseThere arevarious types of magnetic particles available for use in mag-netic particle testing. They are available as dry powders(fluorescent and nonfluorescent) ready for use as supplied (see8.4), powder concentrates (fluoresce
40、nt and nonfluorescent) fordispersion in water or suspending in light petroleum distillates(see 8.5), magnetic slurries/paints (see 8.5.7), and magneticpolymer dispersions (see 8.5.8).4.5 Evaluation of IndicationsWhen the material to beexamined has been properly magnetized, the magnetic particleshave
41、 been properly applied, and the excess particles properlyremoved, there will be accumulations of magnetic particlesremaining at the points of flux leakage. These accumulationsshow the distortion of the magnetic field and are calledindications. Without disturbing the particles, the indicationsmust be
42、 examined, classified, compared with the acceptancestandards, and a decision made concerning the disposition ofthe material that contains the indication.4.6 Typical Magnetic Particle Indications:4.6.1 Surface DiscontinuitiesSurface discontinuities, withfew exceptions, produce sharp, distinct pattern
43、s (see AnnexA1).4.6.2 Near-surface DiscontinuitiesNear-surface disconti-nuities produce less distinct indications than those open to thesurface. The patterns tend to be broad, rather than sharp, andthe particles are less tightly held (see Annex A1).5. Significance and Use5.1 The magnetic particle me
44、thod of nondestructive testingindicates the presence of surface and near-surface discontinui-ties in materials that can be magnetized (ferromagnetic). Thismethod can be used for production examination of parts/components or structures and for field applications whereportability of equipment and acce
45、ssibility to the area to beexamined are factors. The ability of the method to find smalldiscontinuities can be enhanced by using fluorescent particlessuspended in a suitable vehicle and by introducing a magneticfield of the proper strength whose orientation is as close aspossible to 90 to the direct
46、ion of the suspected discontinuity(see 4.3.2). A smoother surface or a pulsed current improvesmobility of the magnetic particles under the influence of themagnetic field to collect on the surface where magnetic fluxleakage occurs.6. Equipment6.1 TypesThere are a number of types of equipmentavailable
47、 for magnetizing ferromagnetic parts and components.With the exception of a permanent magnet, all equipmentrequires a power source capable of delivering the requiredcurrent levels to produce the magnetic field. The current useddictates the sizes of cables and the capability of relays,switching conta
48、cts, meters and rectifier if the power source isalternating current.6.2 PortabilityPortability, which includes the ability tohand carry the equipment, can be obtained from yokes,portable coils with power supplies, and capacitor dischargepower supplies with cables. Generally, portable coils provideFI
49、G. 1 Yoke Method of Part MagnetizationE709 153high magnetizing forces by using higher numbers of turns tocompensate for their lower current flow. Capacitor dischargeunits use high current storage capacity and provide these highcurrent levels for only a very short duration.6.3 YokesYokes are usually C-shaped electromagnetswhich induce a magnetic field between the poles (legs) and areused for local magnetization (Fig. 1). Many portable yokeshave articulated legs (poles) that allow the legs to be adjustedto contact irregular surfaces or two surfaces that join at ana
