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【英文标准名称】:StandardPracticeforElectromagnetic(Eddy-Current)ExaminationofNickelandNickelAlloyTubularProducts
【原文标准名称】:镍及镍合金管形制品的电磁(涡电流)检验的标准实施规程
【标准号】:ASTME571-1998(2007)e1
【标准状态】:现行
【国别】:美国
【发布日期】:1998
【实施或试行日期】:
【发布单位】:美国材料与试验协会(US-ASTM)
【起草单位】:E07.07
【标准类型】:(Practice)
【标准水平】:()
【中文主题词】:
【英文主题词】:discontinuities;eddy-current;electricalresistivity;electromagnetic;encirclingcoil;magneticsaturation;nickel;nickelalloy;pipe(seeNote1);probe;probecoil;tubes;tubularproducts;weldedtubing;Eddycurrentexamination;Electr
【摘要】:Eddy-currentexaminationisanondestructivemethodoflocatingdiscontinuitiesinmetallicmaterials.Signalscanbeproducedbydiscontinuitiesoriginatingoneithertheexternalorinternalsurfacesofthetubeorbydiscontinuitiestotallycontainedwithinthewall.Sincethedensityofeddycurrentsdecreasesnearlyexponentiallywithincreasingdistancefromthesurfacenearestthecoil,theresponsetodeep-seateddefectsdecreasescorrespondingly.Phasechangesarealsoassociatedwithchangesindepth,allowingtheuseofphaseanalysistechniques.Theresponsefromnaturaldiscontinuitiescanbesignificantlydifferentthanthatfromartificialdiscontinuities,suchasdrilledholesornotches.Forthisreason,sufficientworkshouldbedonetoestablishthesensitivitylevelandsetuprequiredtodetectnaturaldiscontinuitiesofconsequencetotheenduseoftheproduct.Someindicationsobtainedbythismethodmaynotberelevanttoproductquality;forexample,anirrelevantindicationmaybecausedbyminutedentsortoolchattermarks,whicharenotdetrimentaltotheenduseoftheproduct.Irrelevantindicationscanmaskunacceptablediscontinuities.Relevantindicationsarethosewhichresultfromdiscontinuities.Anyindicationthatexceedstherejectionlevelshallbetreatedasarelevantindicationuntilitcanbedemonstratedthatitisirrelevant.Generally,eddy-currentexaminationsystemsarenotsensitivetodiscontinuitiesadjacenttotheendsofthetube(endeffect).Discontinuitiessuchasscratchesorseamsthatarecontinuousanduniformoverthefulllengthofthetubemaynotalwaysbedetectedwithdifferentialencirclingcoilsorprobesscannedalongthetubelength.Formaterialthatismagnetic,astrongmagneticfieldshallbeplacedintheregionoftheexaminingcoil.Amagneticfieldmayalsobeusedtoimprovethesignal-to-noiseratiointubingthatexhibitsslightresidualmagnetism.1.1Thispracticecoverstheproceduresforeddy-currentexaminationofnickelandnickelalloytubes.Theseproceduresareapplicablefortubeswithoutsidediametersupto2in.(50.8mm),incl,andwallthicknessesfrom0.035to0.120in.(0.889to3.04mm),incl.Theseproceduresmaybeusedfortubesbeyondthesizerangerecommended,bycontractualagreementbetweenthepurchaserandtheproducer.1.2Theproceduresdescribedinthispracticemakeuseoffixedencirclingtestcoilsorprobesystems.1.3Thevaluesstatedininch-poundunitsaretoberegardedasthestandard.Note18212;Forconvenience,thetermx201C;tubex201D;orx201C;tubularproductx201D;willhereinafterbeusedtorefertobothpipeandtubing.1.4Thisstandarddoesnotpurporttoaddressallofthesafetyconcerns,ifany,associatedwithitsuse.Itistheresponsibilityoftheuserofthisstandardtoestablishappropriatesafetyandhealthpracticesanddeterminetheapplicabilityofregulatorylimitationspriortouse.
【中国标准分类号】:H26
【国际标准分类号】:
【页数】:5P.;A4
【正文语种】:英语