2024年5月3日发(作者：神舟飞船简笔画)

Designation:A388/A388M–03

UsedinUSNRC-RDTstandards

AnAmericanNationalStandard

StandardPracticefor

UltrasonicExaminationofHeavySteelForgings

1

ThisstandardisissuedunderthefixeddesignationA388/A388M;thenumberimmediatelyfollowingthedesignationindicatestheyear

oforiginaladoptionor,inthecaseofrevision,rinparenthesesindicatestheyearoflastreapproval.

Asuperscriptepsilon(e)indicatesaneditorialchangesincethelastrevisionorreapproval.

*

1.1Thispractice

2

coverstheexaminationproceduresforthe

contact,pulse-echoultrasonicexaminationofheavysteel

straightbeamtechniquesincludeutilizationoftheDGS(Dis-

tanceGain-Size)endixX3.

1.2Thispracticeistobeusedwhenevertheinquiry,

contract,order,orspecificationstatesthatforgingsaretobe

subjecttoultrasonicexaminationinaccordancewithPractice

A388/A388M.

1.3Thevaluesstatedineitherinch-poundorSIunitsareto

thetext,theSIunitsare

uesstatedineachsystemarenot

exactequivalents;therefore,eachsystemmustbeusedinde-

ingvaluesfromthetwosystems

mayresultinnonconformancewiththespecification.

1.4Thisspecificationandtheapplicablematerialspecifica-

tionsareexpressedinbothinch-poundunitsandSIunits.

However,unlesstheorderspecifiestheapplicable“M”speci-

ficationdesignation[SIunits],thematerialshallbefurnished

toinch-poundunits.

1.5Thisstandarddoesnotpurporttoaddressallofthe

safetyconcerns,ifany,e

responsibilityoftheuserofthisstandardtoestablishappro-

priatesafetyandhealthpracticesanddeterminetheapplica-

bilityofregulatorylimitationspriortouse.

ncedDocuments

2.1ASTMStandards:

A469SpecificationforVacuum-TreatedSteelForgingsfor

GeneratorRotors

3

A745/A745MPracticeforUltrasonicExaminationofAus-

teniticSteelForgings

3

E317PracticeforEvaluatingPerformanceCharacteristics

ofUltrasonicPulse-EchoExaminationInstrumentsand

SystemsWithouttheUseofElectronicMeasurement

Instruments

4

E428PracticeforFabricationandControlofSteelRefer-

enceBlocksUsedinUltrasonicInspection

4

2.2ANSIStandard:

B46.1SurfaceTexture

5

2.3OtherDocument:

RecommendedPracticeforNondestructivePersonnelQuali-

ficationandCertificationSNT-TC-1A,Supplement

C—UltrasonicTesting

6

ngInformation

3.1Whenthispracticeistobeappliedtoaninquiry,

contract,ororder,thepurchasershallsostateandshallalso

furnishthefollowinginformation:

3.1.1Methodofestablishingthesensitivityinaccordance

with7.2.2and7.3.3(Veeorrectangularnotch),

3.1.1.1Thediameterandtestmetaldistanceoftheflat-

bottomholeandthematerialofthereferenceblockin

accordancewith7.2.2.2,

3.1.2Qualitylevelfortheentireforgingorportionsthereof

inaccordancewith10.3,and

3.1.3Anyoptionsinaccordancewith6.1,6.2,and7.1.11.

tus

4.1Anultrasonic,pulsed,reflectiontypeofinstrumentshall

temshallhaveamini-

mumcapabilityforexaminingatfrequenciesfrom1to5MHz.

Onexaminingausteniticstainlessforgingsthesystemshall

havethecapabilitiesforexaminingatfrequenciesdownto0.4

MHz.

4.1.1Theultrasonicinstrumentshallprovidelinearpresen-

tation(within5%)foratleast75%ofthescreenheight

(sweeplinetotopofscreen).The5%linearityreferredtois

ment

linearityshallbeverifiedinaccordancewiththeintentof

AnnualBookofASTMStandards,Vol03.03.

AvailablefromtheAmericanNationalStandardsInstitute,Inc.,25W.43rd

Street,4thfloor,NewYork,NY10036.

6

AvailablefromtheAmericanSocietyforNondestructiveTesting,1711Arlin-

gateLn.,28518,Columbus,OH43228–0518.

5

4

ThispracticeisunderthejurisdictionofASTMCommitteeA01onSteel,

StainlessSteelandRelatedAlloysandisthedirectresponsibilityofSubcommittee

A01.06onSteelForgingsandBillets.

CurrenteditionapprovedApril10,ally

publishedasA388–eviouseditionA388/A388M–01.

2

ForASMEBoilerandPressureVesselCodeapplicationsseerelatedSpecifi-

cationSA-388/SA-388MinSectionIIofthatCode.

3

AnnualBookofASTMStandards,Vol01.05.

1

*ASummaryofChangessectionappearsattheendofthisstandard.

Copyright©ASTMInternational,100BarrHarborDrive,POBoxC700,WestConshohocken,PA19428-2959,UnitedStates.

1

ofblocksprocessedinaccordancewith

PracticeE317orE428maybeusedtoestablishthespecified

65%instrumentlinearity.

4.1.2Theelectronicapparatusshallcontainanattenuator

(accurateoveritsusefulrangeto610%(+1dB)ofthe

amplituderatio)whichwillallowmeasurementofindications

beyondthelinearrangeoftheinstrument.

4.2SearchUnits,havingatransducerwithamaximum

activeareaof1in.

2

[650mm

2

]with

3

⁄

4

in.[20mm]minimum

to1

1

⁄

8

in.[30mm]maximumdimensionsshallbeusedfor

straight-beamscanning(see7.2);andsearchunitsequipped

from

1

⁄

2

by1in.[13by25mm]to1by1in.[25by25mm]

shallbeusedforangle-beamscanning(see7.3).

4.2.1Transducersshallbeutilizedattheirratedfrequencies.

4.2.2Othersearchunitsmaybeusedforevaluatingand

pinpointingindications.

4.3Couplants,havinggoodwettingcharacteristicssuchas

SAENo.20orNo.30motoroil,glycerin,pineoil,orwater

ntsmaynotbecomparabletooneanother

andthesamecouplantshallbeusedforcalibrationand

examination.

4.4ReferenceBlocks,containingflat-bottomholesmaybe

usedforcalibrationofequipmentinaccordancewith4.1.1and

maybeusedtoestablishrecordinglevelsforstraight-beam

examinationwhensospecifiedbytheorderorcontract.

4.5DGSScales,matchedtotheultrasonictestunitand

transducertobeutilized,maybeusedtoestablishrecording

levelsforstraightbeamexamination,whensospecifiedbythe

scalerangemustbeselectedto

includethefullthicknesscross-sectionoftheforgingtobe

pleofaDGSoverlayisfoundinAppendix

X3.

nelRequirements

5.1Personnelperformingtheultrasonicexaminationstothis

practiceshallbequalifiedandcertifiedinaccordancewitha

writtenprocedureconformingtoRecommendedPracticeNo.

SNT-TC-1Aoranothernationalstandardthatisacceptableto

boththepurchaserandthesupplier.

ationofForgingforUltrasonicExamination

6.1Unlessotherwisespecifiedintheorderorcontract,the

forgingshallbemachinedtoprovidecylindricalsurfacesfor

radialexaminationinthecaseofroundforgings;theendsof

theforgingsshallbemachinedperpendiculartotheaxisofthe

fdiskandrectangular

forgingsshallbemachinedflatandparalleltooneanother.

6.2Thesurfaceroughnessofexteriorfinishesshallnot

exceed250µin.[6µm]unlessotherwiseshownontheforging

drawingorstatedintheorderorthecontract.

6.3Thesurfacesoftheforgingtobeexaminedshallbefree

ofextraneousmaterialsuchasloosescale,paint,dirt,andso

forth.

ure

7.1General:

7.1.1Asfaraspracticable,subjecttheentirevolumeofthe

eofradiiatchange

ofsectionsandotherlocalconfigurations,itmaybeimpossible

toexaminesomesectionsofaforging.

7.1.2Performtheultrasonicexaminationafterheattreat-

mentformechanicalproperties(exclusiveofstress-relief

treatments)butpriortodrillingholes,cuttingkeyways,tapers,

grooves,onfiguration

oftheforgingrequiredforthetreatmentformechanical

propertiesprohibitsasubsequentcompleteexaminationofthe

forging,itshallbepermissibletoexaminepriortotreatmentfor

cases,reexaminetheforging

ultrasonicallyascompletelyaspossibleafterheattreatment.

7.1.3Toensurecompletecoverageoftheforgingvolume,

indexthesearchunitwithatleast15%overlapwitheachpass.

7.1.4Formanualscanning,donotexceedascanningrateof

6in./s[150mm/s].

7.1.5Forautomatedscanning,adjustscanningspeedor

instrumentrepetitionrate,orboth,topermitdetectionofthe

smallestdiscontinuitiesreferencedinthespecificationandto

me

shallthescanningspeedexceedthespeedatwhichan

acceptablecalibrationwasmade.

7.1.6Ifpossible,scanallsectionsofforgingsintwo

perpendiculardirections.

7.1.7Scandiskforgingsusingastraightbeamtechnique

fromatleastoneflatfaceandradiallyfromthecircumference,

wheneverpracticable.

7.1.8Scancylindricalsectionsandhollowforgingsradially

acticable,alsoexam-

inetheforgingintheaxialdirection.

7.1.9Inaddition,examinehollowforgingsbyangle-beam

techniquefromtheoutsidediametersurfaceasrequiredin

7.3.1.

7.1.10Inrecheckingorreevaluationbymanufactureror

purchaserusecomparableequipment,searchunits,frequency,

andcouplant.

7.1.11Forgingsmaybeexaminedeitherstationaryorwhile

pecifiedbythe

purchaser,eithermethodmaybeusedatthemanufacturer’s

option.

7.2Straight-BeamExamination:

7.2.1Forstraight-beamexaminationuseanominal2

1

⁄

4

-MHzsearchunitwheneverpracticable;however,1MHzisthe

preferredfrequencyforcoarsegrainedausteniticmaterialsand

instancesonexaminingcoarse

grainedausteniticmaterialsitmaybenecessarytousea

requenciesmaybeusedif

desirableforbetterresolution,penetrability,ordetectabilityof

flaws.

7.2.2Establishtheinstrumentsensitivitybyeitherthe

reflection,reference-blocktechnique,orDGSmethod(see

AppendixX3foranexplanationoftheDGSmethod).

7.2.2.1Back-ReflectionTechnique(Back-ReflectionCali-

brationApplicabletoForgingswithParallelEntryandBack

Surfaces)—Withtheattenuatorsetatanappropriatelevel,for

example5to1or14dB,adjusttheinstrumentcontrolsto

obtainabackreflectionapproximately75%ofthefull-screen

eforging