文献翻译-压力容器无损检测--球形储罐的无损检测技术

外文翻译NondestructiveTestingofPressureVessels-sphericaltankofnon-destructivetestingtechnologyAbstract:Thesphericaltankisthestorageofdifferenttypesofgasesandliquefiedgases,oneofthecommonlyusedpressurevessel,inthepetroleum,chemical,metallurgicalandurbangassupply,etc.arewidelyused.Sphericalstoragetanksinthemanufacturing,installationandusemayoccuratdifferentstagesoftheshortcomingsand,respectively,withthevariousnon-destructivetestingmethods,includingradiationdetection,ultrasonictesting,magneticparticletesting,penetranttesting,eddycurrenttesting,acousticemissiondetectionandmagneticmemorytestingtechniques.,Respectively,ofthesecharacteristicsofnon-destructivetestingmethods.Keywords:pressurevessel;sphericaltank;non-destructivetesting;SummarySphereinacomprehensiveinspectionbythegeneralmethodofusingconventionalnon-destructivetestingandacousticemissiondetectionmode.Conventionalnon-destructivetestingmethodofthemodel,bothinsideandoutsidethesurfaceoftheweldandweldingpartsscar100%magneticparticleorpenetranttesting,ButtWeldwithin20%100%ultrasonictesting,ultrasonictestingtofinddefectsintheinternalstandardfor-rayteststodeterminethenatureofdefectsandtodeterminetheexactlocationofrework;thisdetectionmethodisgenerallyusedtoweldtheinternalstandardofknowndefectsornodefectsoverasmallsphere,butthedetectiontimerequiredfortestingrelativelylong.Acousticemissiondetectionmethodusingthemodel,afterthefirstsuspendedspherepressuretestandacousticemissiontesting,andthendetectionofacousticemissionactivityofthespecifiedsourcetothesurfaceofthesitetestingandultrasonictestingrepeatabilityand,whereappropriate,theexpansionofthesurfacedetectionratiotomorethan20%oftheultrasonictestingfoundexcessiveinternaldefectdetection-raycameratodeterminethenatureofdefectsandtodeterminetheexactlocationofrework;thisdetectionmethodisgenerallyusedorknowntoweldtheremayexistalargenumberofstandardsphericaldefects,acousticemissiontestingcanidentifyalargenumberofdefectsovertheactivityofrepairingdefects;fordefect-freeoverthesphere,theuseofsuchmodelscanbesignificantlyshortenedthetimetoopencanstestedandreduceproductionlosses.However,Itisworthrecallingthat,forsomesmallsurfacecracks,pressuretestmaynothavetargetedthesourceofacousticemissionsignals,therefore,sometimesacousticemissiontestingcannotbefoundinasmallsurfacecrack.1.1SurfaceDetectionSurfacedetectionmethodisinthesphereofproductiontoconductacomprehensiveinspectionofthenon-destructivetestingmethodofchoice.Surfacedetectionofthedockingsiteforthesphericaltankweld,filletweld,theDepartmentofweldingfixturestoremovesurfacetraces.IronButtWeldsurfacemagneticmaterialscommonlyusedmethodsofmagneticparticletesting,commonlyusedoutsideofthesphereandwetmagneticparticletesting,theinternalconditionsasaresultofpoorlighting,usuallyfluorescentmagneticparticletesting,filletcannotbedetectedusingmagneticpenetranttestingcanbeused.Non-ferrousmagneticpermeabilityofthesurfacetesting,pressurevessel,theinternaluseoffluorescentpenetranttesting,pressurevesselinfiltrationoftheexternaldetectionoftheuseofshading.Basedonyearsoftestingexperience,sphericalsurfacecrackpronepartsofthemainDepartmentofPublicWorkstoremoveweldingfixturestracksurface,thepillarsoffillet,installationringassemblyofthefinalweld(normallyweldthelooponthepole)theoutersurface,mediumsurfacepartsoftheinnersurfaceoftheweld.1.2eddycurrentsurfacecrackdetectionWeldsurfacecrackdetectionofthemagneticpowderorinfiltrationneedtobeseizedpriortocleanweldsurfacetreatment,surfacecoatingortoremovedirt,sonotsuitableforonlinedetectionsphere.Inaddition,thesphere100%opencansbothinsideandoutsidethesurfaceofweldtestingfoundthatmorethan80%ofthesphericalsurfacewithoutanycracks,evenifthesphericalsurfacecrackwasfound,ingeneralthereisonlyafewsurfacecrack,orseamlengthofl%orless,soalotofgrindingontheonehand,anincreaseofsphericaltankproductiontesttimeandcost,ontheotherhand,reducesthesphericalshellthicknessweldparts.Usingeddycurrenttechnologycannotremovethesurfacecoatinginthecaseofmetalmaterialsfromthesurfacetodetectcracks,however,conventionaleddycurrenttestingmethodisonlyapplicabletomaterialsonthesurfaceofthecrack,thecrackoftheweldduetowelditinthefusionofhightemperatureferromagnetismarisingfromthechangesandweldsurfaceappearruggedanddisorderlymagneticinterferencecannotbedetected.Tosolvetheseproblems,peoplehavedevelopedthecomplexplanebasedontheanalysisofweldmetalmaterialelectromagneticeddycurrenttestingtechnology,thereareanti-corrosionlayer,thepointscanalsobeaspecialprobeontheweldsurfaceforrapidscanning,andlift-offeffectonthetestresultstheimpactofverysmall79.Basedontheanalysisofthecomplexplaneeddycurrentsurfacecrackdetectionapparatususingmagneticdisturbancecurrentprobeeddycurrenttestingtechnologytodetectsurfaceweldcracks,thismethodallowsmoreroughweldsurfaceorwithacertainthicknessofcoating,itcanbeusedforballcanrunthecourseoftheoutersurfaceoftheweldoftherapiddetectionofcracks,canalsobeusedforsphericaltankinspectionatthetimeofproduction.Thenthemethodcanbeusedforrapiddetectionoftheweld,andthenpartsofsuspiciouspowderorpenetrationtestingrepeatabilitytodeterminetheexactlocationofsurfacecracksandsize.Thecurrentmarketinthecoatingapparatuscanbe0.2mm,thedetectionsensitivityishigherthan0.5mmdeepsurfacecracklengthof5mm;2mminthecaseofcoating,detectionsensitivityishigherthanlmmlong5mmdeepsurfacecracks;Theinstrumentcanalsobeof5mmdeepDeterminationofcrackdepth.1.3UltrasonicTestingSphericaltankwithacomprehensivetestmethodscommonlyusedultrasonictestingofbuttweldor100%forrandomtesting,todetectinternalweldfatiguecrackmayoccurortheexistenceofhiddendefectsinwelding,forthesphericaltankisnoteasytoopencanalsobedetectedfromtheoutsideseamoftheinnersphericalsurfacecrack,theexternalsphericallayerofinsulationcoveringthesituation,orfromtheinternalsphereoftheoutersurfaceofweldcracksweredetectedthere,butthemethodofultrasonictestingingeneralcanonlybefoundmorethan5mmlonglmmdeepsurfacecracks.Ultrasonicflawdetectorasaresultofsmallsize,lightweight,veryeasytocarryandoperate,andcomparedwiththerayisharmlesstohumanbody,sotheuseofsphericaltanksarewidelyusedintesting.Atpresent,theultrasonictestingofthesphericaltankfounddirectlygeneratedinternallyweldfatiguecrackisveryrare,themainfindingsofultrasonictestingoftheinstallationprocessorundetectedsphericalpores,slag,non-fusionandlackofpenetrationweldingdefects,suchastheoriginal.Manycasesofexcessiveweldingdefectsinthesafetyassessmentofdefectsofthemethodshallbemaintained,andsafetyassessmentofneedtoknowtheirowndeficienciesinthelengthandheight.Thecharacteristicsofultrasonicdetectionmethodismoreaccurateinthedetectionofwelddefectsintheirlengthandheightofthesafetyassessmentfordefectsintheprovisionofdefectivedatageometry.JB4730Thenewlyamendedprovisionsofultrasonicflawdetectionmethoditselfhighlydefectiveendpointdiffractionwavemethod,theendofthelargestand6dBecholaw,butusethehighestmeasurementaccuracyisdefectiveendpointdiffractionwavemethod,theaccuracyofO.5lmm.Inaddition,theTOFDultrasonictestingabroadandholographicimaginghasbeentopromotetheapplicationofmature,theseinternaldefectscanbemoreintuitiveandmoreaccuratedata,thecurrentisalsoactivatedthesemethodsofresearchandapplicationwork,sothefuturethesemethodsinthesphereoftheregulartestingwillplayanimportantrole.1.4-raydetectionPressurevesselsusedforthecomprehensivetest-raydetectionmethodmainlyusedforthickness12mmofPressureVesselsWeldTestinginternalburieddefects,forsheetmetalusingultrasonictestingacertaindegreeofdifficulty,anddoesnotrequiretheuseofhigh-raydetectiontubevoltage.Sphericaltankasaresultofageneralwallthicknessof20mm,suitableforultrasonictesting,themostcomprehensiveinthetestwithspherical-raydetectionmethodseldomused.Butforthe80sbeforethe20thcentury,manufactureandinstallationofthesphere,duetostrictqualitycontrolatthetime,theexistenceofanumberofwelddefectsinalargenumberofstandard,sooftenusedwhenacomprehensivetest7-raydetectionmethod.Detectionofthesourcewillbe7onthecenteroftheinternalsphere,afewhourstocompletethetransilluminationButtWeld100%detectionefficiency.Inaddition,ultrasonictestingfoundexcessivedefects,oftenusedtocomplexinspection-raydetectioninordertofurtherdeterminethenatureofthesedeficienciesandspecificareas,toprovideabasisforrepairingdefects.1.5AcousticemissiontestingAcousticemissionmethodmaybeusedtodetecttheexistenceofsphericalactivedefects,butalsocanbeusedtoevaluatetheactivityofknowndefects10,111.Acousticemissiontestingisdifferentfromothernon-destructivetestingmethods,testingmustbecarriedoutduringtheloadingofthesphericaltank,commonlyusedforpressurevesselloadingmethodstostoprunningafterthewaterpressureorairpressuretest,theworkcanbedirectlyusedtoloadmedia.Defectsoftheactivitydetectedintheloadingprocessisusedinanumberofacousticemissionsensorsonthesphericalshelltotheoverallmonitoring,todiscoverthesourceofacousticemissionactivityanditshostsite,andthenthroughtheactivityofacousticemissionsourceonthesurfaceandinternaldefectdetection,ruleouttheinterferencesourceandfoundthattheexistenceofsphericaldefects.Knowndefectsintheactivityofevaluationiscarriedoutintheloadingprocessacousticemissionmonitoring,iftheentireloadinthecourseofdefectivepartsofthesourcepositionhaveasilentlaunch,itisanon-activityofdefects,onthecontrary,ifalargenumberofacousticemissionlocationsourcesignals,thatistheactivityofthedefects.Throughthecenterofaspecialprosecutorlastdecadeinthefieldofmorethan100cansofacousticemissionbilliardscomprehensiveanalysisoftestdataandfoundthattheacousticemissionsourceofconventionalnon-destructivetestingrepeatabilityresults,Tablelgivesthesphericalsoundfieldemissiontestingmayencounteravarietyoftypicalacousticemissionsourcecategories,anddescribethesourcelocationandmechanismgenerated.1.6MagneticMemoryTestingMetalmagneticmemorytestingtechniqueisProfessorDuBofuRussiainthe20thcentury,early90sandlate90sdevelopedadetectionmaterialstressconcentrationandfatiguedamageofthenewmethodofnondestructivetestinganddiagnosis.Metalmagneticmemorytestingistheuseoftheprincipleofferromagneticworkpiecescontainedinthecourseoftheirwork,stressanddeformationintheregionresultingfromirreversiblechangesinmagneticstate12.Occurredintheregionwiththemagnetostrictivenatureofthemagneticdomain-orientedorganizationsandnon-reversiblere-orientation,andthemagneticstateofirreversiblechangesintheworkloadwillnotonlyretain,aftertheelimination,butalsotheroleofstressrelatedtothelargest.Magneticmemorytestingmaterialscanbefoundafterstresscausedbyfatiguedamage,andevenleadtotheemergenceofcrack;butonthemechanismofmagneticmemoryphenomenonisnotveryclearunderstandingofthegeneralandothernon-destructivetestingmethodsusedtopreventtheleakagedefectseized.Withthesameeddycurrentdetectionmethodsformagneticmemorytestingontheweldsdonothavetodealwithsurfacepolished,withpaintlayercanbedirectlydetectedrapidscanning,sothismethodisparticularlysuitableforon-lineTankdetection.Electromagneticeddycurrenttestingmethodswithdifferentdetectionmethodisamagneticmemoryisfoundtoexistinthesphereofhighstressconcentrationareas,andoftenintheseareaspronetostresscorrosioncrackingandfatiguedamage.Detectionofsphericaltank,theusualmagneticmemorytestingapparatusforsphericaltankweldingseamforquickscanningtodetecttheexistenceofpressurevesselweldpartsofthestresspeak,andthenthepeakstressonthesepartsoflocalsurfacemagneticparticletestingandinternalsuper-sounddetection,todetectpossiblesurfacecracksorinternaldefects.ConclusionNon-destructivetestingtechnologyinthesphereofmanufacturing,installationanduseofprocess,toensurequalityandsafeoperationofitsveryimportantroletoplay.Forthemanufacturingprocessinordertoshellplate-basedultrasonicdetectionmethods;theinstallationprocess,totheWeld-rayorultrasound-baseddetectionmethods;forperiodicinspectionbytheprocesstothesurfaceofdetectionmethodsfordetectionofacousticemissionmain.Inaddition,eddycurrenttestingandmagneticmemorytestingandothernewtechnologyintheonlinetestinghasbeguntobeapplied.Itcanbeexpected,withthenewnon-destructivetestingtechnology,isboundtohavesomefasterdetection,highersensitivityandreliability,defectshowedamoreintuitivenewmethodsofdetectioninthesphereofapplication.压力容器无损检测-球形储罐的无损检测技术摘要：球形储罐是储存各种气体和液化气体的常用压力容器之一，在石油、化工、冶金和城市燃气供应等方面得到广泛使用。球形储罐在制造、安装和使用过程中不同阶段可能出现的缺陷和分别采用的各种无损检测方法，包括射线检测、超声检测、磁粉检测、渗透检测、电磁涡流检测、声发射检测和磁记忆检测等技术。分别介绍了这些无损检测方法的特点。关键词：压力容器；球形储罐；无损检测；综述目前在用球罐全面检验一般采用常规无损检测方法和声发射检测方法两种模式。常规无损检测方法的模式为，对内外表面焊缝和焊疤部位进行100磁粉或渗透检测，对接焊缝内部进行20100超声检测，对超声检测发现的内部超标缺陷进行射线检测以确定缺陷的性质，并为返修确定具体部位；这种检测方法一般用于焊缝内部无已知超标缺陷或超标缺陷很少的球罐，但这种检测方法所需的检验时间相对较长。采用声发射检测方法的模式为，球罐停用后首先进行水压试验和声发射检测，然后对声发射检测指定的活性源部位进行表面检测和超声检测复验，并适当扩大表面检测的比例到20以上，对超声检测发现的内部超标缺陷进行射线检测照相以确定缺陷的性质，并为返修确定具体部位；这种检测方法一般用于已知焊缝内部存在或可能存在大量超标缺陷的球罐，声发射检测可以从大量超标缺陷中识别出活性缺陷进行返修；对于无超标缺陷的球罐，采用此种模式，也可大大缩减开罐检验的时间，减少停产损失。然而，值得提醒的是，对于一些较小的表面裂纹，耐压试验过程中可能不产生声发射定位源信号，因此，声发射检测有时不能发现小的表面裂纹。1.1表面检测表面检测方法是在球罐停产进行全面检验中首选的无损检测方法。表面检测的部位为球罐的对接焊缝、角焊缝、工卡具拆除处的焊迹表面等。铁磁性材料对接焊缝的表面一般采用磁粉检测方法，球罐的外部一般采用湿式黑磁粉检测，内部由于照明条件不好，通常采用荧光磁粉检测，角焊缝无法采用磁粉检测时可用渗透检测。非铁磁性材料的表面采用渗透检测，压力容器的内部采用荧光渗透检测，压力容器的外部采用着色渗透检测。根据多年的检验经验，球罐容易出现表面裂纹的部位主要有工卡具拆除处的焊迹表面、支柱角焊缝、安装时组装的最后一道环焊缝(一般为上极圈环焊缝)的外表面，介质液面部位的焊缝内表面。1.2电磁涡流表面裂纹检测焊缝表面裂纹的磁粉或渗透检测都需要将被检焊缝表面事先进行清洁处理，除去表面防腐层或污垢，因此不适合球罐的在线检测。另外，球罐开罐100焊缝内外表面的检测发现，80以上的球罐无任何表面裂纹，即使发现表面裂纹的球罐，一般也是只存在几处表面裂纹，占焊缝总长的l以下，因此大量的打磨一方面增加了球罐停产检验的时间和费用，另一方面也减小了球罐焊缝部位壳体的壁厚。采用涡流技术可在不去除表面涂层的情况下来探测金属材料的表面裂纹，然而，常规涡流方法只适用于检测表面光滑母材上的裂纹，对焊缝上的裂纹却会因焊缝在高温熔合时产生的铁磁性变化和焊缝表面高低不平而出现杂乱无序的磁干扰而无法检测。针对这些问题，人们研究出基于复平面分析的金属材料焊缝电磁涡流检测技术，在有防腐层时，也可用特殊的点式探头对焊缝表面进行快速扫描检测，而且提离效应对检测结果的影响很小79。基于复平面分析的电磁涡流表面裂纹检测仪器采用电流扰动磁敏探头的涡流检测技术来检测焊缝的表面裂纹，此方法允许焊缝表面较为粗糙或带有一定厚度的防腐层，因此可用于球罐运行过程中的焊缝外表面裂纹的快速检测，也可用于球罐停产时的全面检验。这时可先采用该方法对焊缝进行快速检测，然后对可疑部位进行磁粉或渗透检测复验，以确定表面裂纹的具体部位和大小。目前市场上销售的仪器可在涂层0.2mm的情况下，检测灵敏度高于0.5mm深5mm长的表面裂纹；在有2mm涂层的情况下，检测灵敏度高于lmm深5mm长的表面裂纹；该仪器还可对5mm深的裂纹进行深度测定。1.3超声检测在用球罐的全面检验一般采用超声检测方法对对接焊缝进行抽查或100检测，以发现焊缝内部可能出现的疲劳裂纹或已存在的焊接埋藏缺陷，对于不易打开的球罐也可从外部检测球罐焊缝的内表面裂纹，对于球罐外部有保温覆盖层的情况，也可从球罐的内部对焊缝外表面出现的裂纹进行检测，但超声检测方法一般只能发现lmm深5mm长以上的表面裂纹。由于超声波探伤仪体积小、重量轻，十分便于携带和操作，而且与射线相比对人体无害，因此在在用球罐检验中得到广泛使用。目前，对球罐的超声检测中直接发现焊缝内部产生的疲劳裂纹是很少见的，超声检测主要发现的还是球罐安装过程中漏检的气孔、夹渣、未熔合和未焊透等原始焊接缺陷。许多情况下对超标的焊接缺陷采取缺陷安全评定的方法予以保留，而安全评定需要知道缺陷的长度和自身高度。超声检测方法的特点是可以较精确测出焊缝内缺陷的长度和自身高度，为缺陷的安全评定提供缺陷的几何尺寸数据。新修订的JB4730规定超声检测缺陷自身高度测量方法有缺陷端点衍射波法、端部最大回波法和6dB法等，但目前使用测量精度最高的方法是缺陷端点衍射波法，精度达O5lmm。另外，在国外超声检测的TOFD