1、Designation:A966/A966M15Standard Practice forMagnetic Particle Examination of Steel Forgings UsingAlternating Current1This standard is issued under the fixed designation A966/A966M;the number immediately following the designation indicates the yearof original adoption or,in the case of revision,the
2、year of last revision.A number in parentheses indicates the year of last reapproval.A superscript epsilon()indicates an editorial change since the last revision or reapproval.1.Scope*1.1 This practice covers a procedure for the magneticparticle examination of steel forgings using alternating current
3、as the power source.The procedure will produce consistentresults upon which acceptance standards can be based.Thispractice does not contain acceptance limits or recommendedquality levels.1.2 Only alternating 5060 cycle current shall be used as theelectric power source for any of the magnetizing meth
4、ods.1.3 When subsurface indications are sought in forgings,then dc magnetization in accordance with Practice A275/A275M should be used.1.4 The values stated in either inch-pound units or SI unitsare to be regarded separately as standard.Within the text,theSI units are shown in brackets.The values st
5、ated in eachsystem are not exact equivalents;therefore each system shallbe used independently of the other.Combining values from thetwo systems may result in nonconformance with the specifi-cation.Unless the order specifies the applicable“M”specifi-cation designation SI units,the inch-pound units sh
6、all beused.1.5 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 practices and determine the applica-bility of regulatory limitations prior to use.2.Refer
7、enced Documents2.1 ASTM Standards:2A275/A275M Practice for Magnetic Particle Examination ofSteel ForgingsA508/A508M Specification for Quenched and TemperedVacuum-Treated Carbon and Alloy Steel Forgings forPressure VesselsA788/A788M Specification for Steel Forgings,General Re-quirementsA963/A963M Spe
8、cification for Deep Drawing Steel(DDS),Sheet,Carbon,Cold-Rolled(Withdrawn 2000)32.2 Other Document:Practice No.SNT-TC-1A,Supplement BMagnetic Par-ticle Method43.Terminology3.1 Definitions:3.1.1(ac)magnetic particle method of examination,namethod for detecting discontinuities on the surface in suitab
9、lymagnetized materials,which employs finely divided magneticparticles that tend to congregate in regions of leakage fields.3.1.2 indication,nthe visual magnetic particle buildupresulting from leakage fields in the magnetic field.3.1.3 linear indication,nan indication in which the lengthis at least t
10、hree times the width.The minimum length ofindications to be considered linear shall be116in.1.5 mm.3.1.4 magnetic flux,nthe product of the magnetic induc-tion and the area of a surface(or cross section)when themagnetic induction is uniformly distributed and normal to theplane of the surface.3.1.4.1
11、DiscussionThe concept that the magnetic field isflowing along the lines of force suggests that these lines aretherefore“flux”lines,and they are called magnetic flux.3.1.5 nonrelevant indications,nindications produced byleakage fields where the conditions causing them are present byaccident or part d
12、esign,or other features of the part having norelation to the damaging flaws being sought.3.1.5.1 DiscussionThis term signifies that such an indica-tion has no relation to the discontinuities that might constitutedefects.1This practice is under the jurisdiction of ASTM Committee A01 on Steel,Stainles
13、s Steel and Related Alloys and is the direct responsibility of SubcommitteeA01.06 on Steel Forgings and Billets.Current edition approved May 1,2015.Published May 2015.Originallyapproved in 1996.Last previous edition approved in 2012 as A966/A966M 08(2012).DOI:10.1520/A0966_A0966M-15.2For referenced
14、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.3The last approved version of this historical standard is referenced onwww.astm.or
15、g.4Available fromAmerican Society for Nondestructive Testing(ASNT),P.O.Box28518,1711 Arlingate Ln.,Columbus,OH 43228-0518,http:/www.asnt.org.*A Summary of Changes section appears at the end of this standardCopyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959
16、.United States1 4.Basis of Application4.1 When in accordance with the requirements of theinquiry,contract,order,or specifications,forgings are to beexamined by the magnetic particle method using alternatingcurrent;the manufacturer and the supplier shall be in agree-ment concerning the following:4.1.1 The locations on the forging that are to be subjected tomagnetic particle examination.4.1.2 The type,size,number,location,and orientation ofindications that are to be considered injurious.4.1.3 The