MILITARY STANDARD - adc-ga.com

1 NOTMEASUREMENTSENSITIVEMIL-STD 1949A~~MAY19(J9,..,SUPERSEDINGMIL-STD 19491 AUGUST198 MILITARYSTANDARDINSPECTION,MAGNETICPARTI CLE5II()I)ELIVEHALILEDATAREQLJIRE~UY rlllSDOCUMENTAMscl iiAAREANOT!,,[)1ST1 lll?UllONSTATEMEt{TAApprovedforpublicrel ease;. , , (recommendations,additions,deletions)and anypertinentdatawhichmaybeofuseinimprovi ngthisdocumentshouldbeaddressedto:Direct or, ,ATTN:SLCMT-MEE,Watertown,MA02172-0001by usingtheStandardizationDocumentImproveme ntProposal(DDForm1426) , *2* *wlOl* + , ,drawings, *lw9 *llll-l =l *l -w - sl -Indication.]}

2 L lIndication, Indication, * l. l * =l + l ll . \ * * ,.. ,..,.. ,; = + MIL-STD-1949 AcONTENTSC alculatingtheL/Dratioforcylindricalpart. ,.. *,**. **.**.**.**.**.l.<.** ~ ,.. :.. , l l llStamping, , , *.. ( *.. ) .. *., , standards , , standards , ,theissuesofthesedocumentsarethoselisted intheissueoftheDepartmentofDefenseIndexo fSpecificationsandStandards(DODISS)andsu pplementthereto, ,MagneticRubberDOD-F-87935-Fluid,Magneti cParticleInspection,Suspension(Metric)

3 STANDARDSFEDERALFED-STD-31 ,LiquidPenetrantandMagneticParticleSound nessRequirementsForMaterials,PartsandWel dmentsNondestructiveTestingPersonnelQual ificationandCertificationCastings,Classi ficationandInspectionofCalibrationSystem sRequirementsUnlessotherwiseindicated,co piesoffederalandmilitaryfications,standa rds,andhandbooksareavailablefromtheNaval cationsandFormsCenter,(ATTN:NPODS),5801 TaborAvenue,philadelphia~PA19120-5099.) ,drawings, ,drawings, , (OSHA)CodeofFederalRegulationsisavailabl efromtheSuperintendentofDocuments, ,Washington,DC20402- U !

4 Y2 UIREF! ,laps,seams,inclusions, ,billets,finishedandsemifinishedmaterial s,welds,andIn-se; ,termed fluxleakage=, ,applicationofsuitablypreparedmagneticpa rticleswhilethe-areaismagnetizedorbeingm agnetized,andsubsequentclassification,in terpretation, ,alengthatleastequaltoitsdepth, ,eticfields,perpendiculartooneanotherina planeparalleltothesurfacebeinginspecteds hallbeused, documentsshallspecifytheacceptablesizean dconcentrationofdiscontinuitiesforthecom ponent, ,Thewrittenproceduremaybeageneraloneifit clearlyappliestoallthespecifiedpartsbein gtestedandmeetstherequirementsof\.

5 ,LevelIIIformagneticparticleinspection, , ( ).Areasoftheparttobeexamined(includeaske tchifnecessary).Directionsofmagnetizatio ntobeused,theorderinwhichtheyareapplied, (prods~yoke~cablewrap~etc). ,orthenumberofampere-turns~ (dryorwet,visibleorfluorescent,etc.)tobe used,themethodandequipmenttobeusedforits application,and,forthecaseofwetparticles , , ,filed, , ; (directmethod),byinducingacurrenttoflowi nthepartundertest(inducedcurrentmethod), orbyplacingthematerialwithinthemagneticf luxofanexternalsourcesuchasacoil(indirec tmethod).

6 Thetypesofequipmentavailableincludeyokes ,portableunits,mobileunits,stationaryuni ts,andspecialapplicationunits( multidirectionalfield).Thetypesofcurrent susedformagnetizationare7 MIL-STD-1949 Afull-waverectifiedalternatingcurrent,ha lf-waverectifiedalternatingcurrent, ,asoutlinedherein, ,butarenotlimitedto,forging,heattreating ,plating,passivation,coldforming,welding ,grinding,straightening,machining, , , (100foot-candles).Fluorescentmagneticpar ticleinspectionshallbeperformedinadarken eda reawithamaximumambientvisiblelightlevelo f20lux(2foot-candles).

7 +4/cu12whenmeasuredat380mm(15inches) (drymethod),forsuspensionatagivenconcent rationinasuitableliquid(wetmethod),forsu spensioninapolymerizeablematerial(magnet icrubbermethod),orforsuspensioninaslurry (magneticpainting). ,shape, ,freefromrust,grease,paint, :MIL-STD-1949A-Placeaconductorwithadiame terbetween25and31mm( )andalengthgreaterthan40cm(16inches) , ( ). ,AMS3042,AMS3043,AMS3044,AMS3045,orAMS30 46, ,theparticlesshallshowindicationsasliste dintableIonthetestringspecimenoffigure1u singthefollowingprocedure:Placeaconducto rwithadiameterbetween25and31m( )andalengthgreaterthan40cm(16inches) (examinationofnonfluorescentbathsshallbe underavisiblelightofnotlessthan1000lux( );examinationoffluorescentbathsshallbeun derablacklightwithaminimumintensityof100 0~W/cm2atthesurface).

8 Minimumnumberofholeindicationsshallmeeto rexceedthosespecifiedintableI.\ (Type I) ,AMS2641(Type11) ,itshallbesuitablyconditionedtoprovidefo rproperwetting,particledispersion, ( ).Generally, , ,clean,dry,andfreeofoil,scale,machiningm arks, ( ) ( ) , , ,smallopeningsandoilholesleadingtopassag esorcavitiesthatcouldentraporremainconta minatedwithinspectionmediashallbeplugged ormaskedwithasuitablenon-abrasivemateria lwhichcanbereadilyremovedand,inthecaseof engineparts, ,suchascertain-non-metallics, , (electromagneticprobes)

9 Formagneticparticleinspection, ,half-waverectxfiedalternatingcurrent, smanualortheequipmentmanufacturershouldb econsultedtodeterminewhatcorrectionfacto r,ifany, (3/4inch)inthicknessorless, (90to115A/in) (3/4inch)inthickness, (100to125A/in) (2inches)orgreaterthan200mm(8inches).The effectivewidthofthemagnetizingfieldwhenu sing ( headshots-)thecurrentshallbefrom12 Apermmofpartdiameterto32 Apermmofpartdiameter(300to800A/in). (500A/in)orlowerwiththehighercurrents(uP to800A/in)beingusedtoinspectforinclusion $ ,upto40 Apermm(1000A/in) ~thediametershallbethelargestdistancebet weentwopoints, , ,2( Directcircularmagnetization ) ,Whentheconductorpassingthroughtheinside ofthepartisplacedagainstaninsidewallofth epart, ( Directcircularmagnetlzatlon ) (interiororexterior)whichiseffectivelyma gnetizedshallbetakenasfourtimesthediamet erofthecentralconductor , ~orSectionofthepart,tobetested( coilshotm).

10 (seefigure4).Forcablewraporhighfillfacto rcoils,theeffectivedistanceofmagnetizati onis230 mm(9inches)oneithersideofthecoilcenter(s eefigure5).Forpartslongerthantheeeeffect ivedistances,theentirelengthshallbeinspe ctedbyrepositioningthepartwithinthecoil, ,thentheproductofthenumberofcoilturns,N, andthecurrentinamperesthroughthecoil,I,s hallbe ;\ (:10%)L/DwhereK=45,000ampereturnsL=lengt hofthePartD=diameterofthepart(measuredin thesameunitsasthelength) :NI=KR(~lo%)(6L/D)-5whereR=radiusoftheco ilin~(orininches) ~(43,000ampereturnsperinchifRismeasuredi ninches)L=thelengthofthepartD=thediamete rofthepart(measuredinthesameunitsasthele ngth) ,polepieces(piecesofferromagneticmateria lwiththesamediameterasthep artbeingtested) ,thevalue15 (includinghollowportions)ofthepartundert est,thenthe-productofthenumberofcoilturn s,N,andthecurrentinamperesthroughthecoil ,1,shallbe.