AWS D1.1介绍课件.ppt

AWSD1.1,AWSD1.1,AmericanWeldingSociety(美国焊接协会)Thiscodecoverstheweldingrequirementsforanytypeofweldedstructuremadefromthecommonlyusedcarbonandlow-alloyconstructionalsteels.Clauses1through8constituteabodyofrulesfortheregulationofweldinginsteelconstruction.Thereareninenormativeandtwelveinformativeannexesinthiscode.ACommentaryofthecodeisincludedwiththedocument.本规范包含对常用碳素钢和低合金结构钢的任何类型结构的焊接要求。第1章至第8章构成了钢结构焊接规范条例的主体。规范中载有标准性附录9则和信息性附录12则。文件还包括对规范条文的说明。,AWSD1.1,1.GeneralRequirements总则2.DesignofWeldedConnection.焊接连接的设计3.PrequalificationofWPSsWPS的免除评定4.Qualification评定5.Fabrication建造6.Inspection检验7.StudWelding螺柱焊8.StrengtheningandRepairofExistingStructures现有结构的补强与修理,5.Fabrication,5.1范围5.2母材5.3焊接材料的要求5.4ESW和EGW方法5.5WPS参数5.6预热和层间温度5.7调质钢的焊接热输入控制5.8消除应力热处理5.9衬垫、背部保护气体或嵌条5.10衬垫5.11焊接和切割设备5.12焊接环境5.13符合设计要求5.14最小角焊缝5.15母材的准备5.16凹角,5.17梁的开槽口和焊缝的穿越孔5.18定位焊缝和结构辅助焊缝5.19组装部件的拱度5.20周期载荷结构的拼接5.21变形和收缩的控制5.22接头尺寸公差5.23焊接结构部件的尺寸公差5.24焊缝剖面外形5.25塞焊和槽焊技术5.26返修5.27锤击5.28捻缝5.29电弧击伤5.30焊缝清理5.31焊缝引弧板和引出板,AWSD1.1,5.Fabrication5.26Repairs返修Theremovalofweldmetalorportionsofthebasemetalmaybedonebymachining,grinding,chipping,orgouging.Itshallbedoneinsuchamannerthattheadjacentweldmetalorbasemetalisnotnickedorgouged.Oxygengougingshallnotbeusedinquenchedandtemperedsteel.Unacceptableportionsoftheweldshallberemovedwithoutsubstantialremovalofthebasemetal.Thesurfacesshallbecleanedthoroughlybeforewelding.Weldmetalshallbedepositedtocompensateforanydeficiencyinsize.焊缝金属或部分母材的清除可用机加工、打磨、铲凿或刨槽的方法进行。清除必须这样：不在邻近焊缝金属或母材上造成缺口或槽痕。调质钢上严禁使用氧气刨槽。焊缝的不合格部分必须清除但不要伤及母材。焊接之前，必须彻底清洁表面。对于任何尺寸的不足必须熔敷焊缝金属加以补偿。,AWSD1.1,5.Fabrication5.26Repairs返修5.26.1Thecontractorhastheoptionofeitherrepairinganunacceptableweldorremovingandreplacingtheentireweld,exceptasmodifiedby5.26.3.Therepairedorreplacedweldshallberetestedbythemethodoriginallyused,andthesametechniqueandqualityacceptancecriteriashallbeapplied.Ifthecontractorelectstotheweld,itshallbecorrectedasfollows:除按5.26.3要求的修正外，承包商可以选择返修不合格的焊缝，或者清除整条焊缝而重焊。返修或重焊的焊缝必须按原方法再检测，并且使用同样的技术和质量合格判据。如果承包商选择返修焊缝，必须按如下要求进行：,AWSD1.1,5.26.1.1Overlap,ExcessiveConvexity,orExcessiveReinforcement.焊瘤、过分凸起或余高过大Excessiveweldmetalshallberemoved.必须清除过量的焊缝金属。5.26.1.2ExcessiveConcavityofWeldorCrater,UndersizeWelds,Undercutting.Thesurfacesshallbeprepared(see5.30)andadditionalweldmetaldeposited.过分的焊缝内凹或弧坑，焊缝尺寸不足，咬边必须对表面进行准备（见5.30），并熔敷补充的焊缝金属。,AWSD1.1,5.26.1.3IncompleteFusion,ExcessiveWeldPorosity,orSlagInclusions.未融合，过多的焊缝气孔或夹渣Unacceptableportionsshallberemoved(see5.26)andrewelded.清除不合格部分并重焊。,AWSD1.1,5.26.1.4CracksinWeldorBaseMetal.Theextentofthecrackshallbeascertainedbyuseofacidetching,MT,PT,orotherequallypositivemeans;thecrackandsoundmetal2in.50mmbeyondeachendofthecrackshallberemoved,andrewelded.焊缝或母材裂纹应用酸蚀、磁粉检查、渗透检验或其他可靠的方法确定裂纹的范围；还应清除裂纹和超出裂纹每一端50mm的完好金属并重焊。,AWSD1.1,5.26.3EngineersApproval.PriorapprovaloftheEngineershallbeobtainedforrepairstobasemetal,repairofmajorordelayedcracks,repairstoESWandEGWwithinternaldefects,orforareviseddesigntocompensatefordeficiencies.TheEngineershallbenotifiedbeforeweldedmembersarecutapart.工程师认可母材的返修、重要的或延迟裂纹的返修、对有内部缺陷的电渣焊缝和气电焊缝的返修、或由于修改设计而对缺损处进行补偿返修，必须事先得到工程师的同意。割开焊接构件前必须通知工程师。,5.26.4InaccessibilityofUnacceptableWelds.难以返修的焊缝If,afteranunacceptableweldhasbeenmade,workisperformedwhichhasrenderedthatweldinaccessibleorhascreatednewconditionsthatmakecorrectionoftheunacceptablewelddangerousorineffectual,thentheoriginalconditionsshallberestoredbyremovingweldsormembers,orboth,beforethecorrectionsaremade.Ifthisisnotdone,thedeficiencyshallbecompensatedforbyadditionalworkperformedconformingtoanapprovedreviseddesign.已经造成不合格焊缝后，如果由于工作结束而使该不合格焊缝难以接近，或者出现新的情况、给返修工作带来危险或不能返修成功，那么返修前就必须清除焊缝或构件，或两者都除去，以恢复原有条件。如果不进行这一工作，则必须按照得到认可的修改设计实施追加的工作来补偿该缺陷。,AWSD1.1,5.29ArcStrikes电弧击伤Arcstrikesoutsidetheareaofpermanentweldsshouldbeavoidedonanybasemetal.Cracksorblemishescausedbyarcstrikesshallbegroundtoasmoothcontourandcheckedtoensuresoundness.对于任何母材都应避免在永久性焊缝区域以外引燃电弧。电弧击伤导致的裂纹或损伤必须打磨成光滑外形，并作检查以保证金属完好。,AWSD1.1,5.30WeldCleaning焊缝清理5.30.1In-ProcessCleaning过程中的清理Beforeweldingoverpreviouslydepositedmetal,allslagshallberemovedandtheweldandadjacentbasemetalshallbecleanedbybrushingorothersuitablemeans.Thisrequirementshallapplynotonlytosuccessivelayersbutalsotosuccessivebeadsandtothecraterareawhenweldingisresumedafteranyinterruption.Itshallnot,however,restricttheweldingofplugandslotweldsinconformancewith5.25.在焊接覆盖前道熔敷金属以前，必须清除所有焊渣，同时焊缝及邻近的母材必须擦刷或用其他合适的方法清理干净。这一要求不仅必须实施于逐次的焊层，而且必须实施于逐次的焊道以及任何中断焊接对弧坑区域的清理。但按照5.25要求进行的塞焊和槽焊必须不受此限制,AWSD1.1,5.30.2CleaningofCompletedWelds.完工焊缝的清理Slagshallberemovedfromallcompletedwelds,andtheweldandadjacentbasemetalshallbecleanedbybrushingorothersuitablemeans.Tightlyadherentspatterremainingafterthecleaningoperationisacceptable,unlessitsremovalisrequiredforthepurposeofNDT.Weldedjointsshallnotbepainteduntilafterweldinghasbeencompletedandtheweldaccepted.必须清除所有完工焊缝的焊渣，并必须将焊缝及邻近的母材刷干净或用其他适当方法清理。清理后仍牢固粘附的飞溅残余物允许留存，为了无损检测而必须清除者除外。直到焊接工作已经完成并且焊缝验收合格为止，严禁焊缝涂漆。,AWSD1.1,6Inspection,PartAGeneralRequirementsPartBContractorResponsibilitiesPartCAcceptanceCriteriaPartDNDTProceduresPartERadiographicTesting(RT)PartFUltrasonicTesting(UT)ofGrooveWeldsPartGOtherExaminationMethods,AWSD1.1,6.1ScopeClause6containsalloftherequirementsfortheInspectorsqualificationsandresponsibilities,acceptancecriteriafordiscontinuities,andproceduresforNDT.第6章包括对检验人员的资格评定与职责的所有要求，缺陷的验收准则，以及无损检测（NDT）工艺,PartAGeneralRequirements,AWSD1.1,PartBContractorResponsibilities,6.6.1ContractorResponsibilities.承包商责任6.6.2InspectorRequests.检验员要求6.6.3EngineeringJudgment.工程判断6.6.4SpecifiedNDTOtherthanVisual.除目检外规定的NDT6.6.5NonspecifiedNDTOtherthanVisual.除目检外未规定NDT,AWSD1.1,PartCAcceptanceCriteria,6.7ScopeAcceptancecriteriaforvisualandNDTinspectionoftubularconnectionsandstaticallyandcyclicallyloadednontubularconnectionsaredescribedinPartC.Theextentofexaminationandtheacceptancecriteriashallbespecifiedinthecontractdocumentsoninformationfurnishedtothebidder.C部分述及管材连接以及静荷载和周期荷载的非管材连接的外观检验和NDT的验收判据，检查的范围和验收判据必须根据提供给投标者的资料在合同文本中规定。,AWSD1.1,PartCAcceptanceCriteria,6.9VisualInspectionAllweldsshallbevisuallyinspectedandshallbeacceptableifthecriteriaofTable6.1aresatisfied.所有焊缝必须目检，且如满足表6.1所列的条件即必须认为合格。,AWSD1.1,PartCAcceptanceCriteria,6.10PTandMTWeldsthataresubjecttoMTandPT,inadditiontovisualinspection,shallbeevaluatedonthebasisoftheapplicablerequirementsforvisualinspection.Thetestingshallbeperformedinconformancewith6.14.4or6.14.5,whicheverisapplicable.除进行目检外还需进行磁粉检测和液体渗透检测的焊缝，必须在目检合格要求的基础上进行评定。两种检测必须符合6.14.4或6.14.5的适用条款的要求,AWSD1.1,PartCAcceptanceCriteria,6.11NDTExceptasprovidedforin6.18,allNDTmethodsincludingequipmentrequirementsandqualifications,personnelqualifications,andoperatingmethodsshallbeinconformancewithSection6,Inspection.Acceptancecriteriashallbeasdescribedinthissection.WeldssubjecttoNDTshallhavebeenfoundacceptablebyvisualinspectioninconformancewith6.9.除6.18的内容外，所有NDT方法，包括设备要求和鉴定，人员资格评定和操作方法，均必须符合第6章的规定。验收判据必须按本章的规定。需作无损检测的焊缝必须先按6.9规定目检合格。,AWSD1.1,PartCAcceptanceCriteria,6.11NDTForweldssubjecttoNDTinconformancewith6.10,6.11,6.12.3,and6.13.3,thetestingmaybeginimmediatelyafterthecompletedweldshavecooledtoambienttemperature.AcceptancecriteriaforASTMA514,A517,andA709Grade100and100WsteelsshallbebasedonNDTperformednotlessthan48hoursaftercompletionofthewelds.根据6.10，6.11，6.12.1和6.13.3要求作无损检测的焊缝，可以在完工焊缝冷却至环境温度后立即开始检测。对ASTMA514、A517钢和A709100及100W级钢，则规定必须在焊缝完工后至少48小时才能按对这些钢的验收判据作无损检测。,AWSD1.1,PartCAcceptanceCriteria,6.11.1TubularConnectionRequirements.ForCJPgroovebuttweldsweldedfromonesidewithoutbacking,theentirelengthofallcompletedtubularproductionweldsshallbeexaminedbyeitherRTorUT.Theacceptancecriteriashallconformto6.12.3or6.13.3asapplicable.对无衬垫、从一面焊接的CJP坡口接焊缝，对完工的管材产品焊缝的全长必须用射线或超声波检测进行检查。验收判据必须符合6.12.1或6.13.3中适用者。,AWSD1.1,PartDNDTProcedures,6.14Procedures工艺TheNDTproceduresasdescribedinthiscodehavebeeninuseformanyyearsandprovidereasonableassuranceofweldintegrity;however,itappearsthatsomeusersofthecodeincorrectlyconsidereachmethodcapableofdetectingallunacceptablediscontinuities.UsersofthecodeshouldbecomefamiliarwithallthelimitationsofNDTmethodstobeused,particularlytheinabilitytodetectandcharacterizeplanardiscontinuitieswithspecificorientations.(ThelimitationsandcomplementaryuseofeachmethodareexplainedinthelatesteditionofAWSB1.10,GuideforNondestructiveExaminationofWelds.)本规范所述无损检测（NDT）工艺已使用多年，并且对焊缝完好性提供了合理的保证；然而看起来有些规范使用者不正确地认为每一种方法都能检测所有不合格的不连续性。规范使用者应当熟谙每一种所用的无损检测方法的局限性，尤其是无法探测并确定具有特定危害性取向的平面不连续性。（在AWSB1.10焊缝无损检查指南的最新版中阐明了每一种方法的限定及补充使用）。,AWSD1.1,PartDNDTProcedures,6.14.1RT:WhenRTisused,theprocedureandtechniqueshallbeinconformancewithPartEofthissection.当使用射线照相检测时，其工艺和技术必须符合本章E部分的要求6.14.3UT:WhenUTisused,theprocedureandtechniqueshallbeinconformancewithPartFofthissection.当使用超声波检测时，其工艺和技术必须符合本章F部分的要求。,AWSD1.1,PartDNDTProcedures,6.14.4MT.WhenMTisused,theprocedureandtechniqueshallbeinconformancewithASTME709,andthestandardofacceptanceshallbeinconformancewithSection6,PartC,ofthiscode,whicheverisapplicable.当使用磁粉检测时，其工艺和技术必须符合ASTME709的规定，而合格标准则必须符合本规范第6章C部分的要求，取其适用者。,AWSD1.1,PartDNDTProcedures,6.14.5PT.Fordetectingdiscontinuitiesthatareopentothesurface,PTmaybeused.ThestandardmethodssetforthinASTME165shallbeusedforPTinspection,andthestandardsofacceptanceshallbeinconformancewithSection6,PartC,ofthiscode,whicheverisapplicable.当探测表面开口的不连续性时，可以使用着色渗透检测。根据适用情况，必须将ASTME165中规定的标准方法用于着色渗透检测，而合格标准应符合本规范第6章C部分适用规定的要求。,AWSD1.1,6.14.6PersonnelQualification人员资格评定6.14.6.1ASNTRequirements.PersonnelperformingNDTotherthanvisualshallbequalifiedinconformancewiththecurrenteditionoftheAmericanSocietyforNondestructiveTestingRecommendedPracticeNo.SNT-TC-1A.IndividualswhoperformNDTshallbequalifiedfor:(1)NDTLevelII,or(2)NDTLevelIworkingundertheNDTLevelII,PartDNDTProcedures,AWSD1.1,PartDNDTProcedures,6.15ExtentofTesting检验范围6.15.1FullTesting.完全检验Weldjointsrequiringtestingbycontractspecificationshallbetestedfortheirfulllength,unlesspartialorspottestingisspecified.除规定作局部检测或抽检外，按照合同技术规定要求检测的焊缝接头必须全长度检测,AWSD1.1,6.15.2PartialTesting.局部抽检Whenpartialtestingisspecified,thelocationandlengthsofweldsorcategoriesofweldtobetestedshallbeclearlydesignatedinthecontractdocuments.当规定作局部检测时，必须在合同文本中清晰地标明待检测的焊缝部位和长度，或者待检测焊缝的类别,PartDNDTProcedures,AWSD1.1,6.15.3SpotTesting.抽检Whenspottestingisspecified,thenumberofspotsineachdesignatedcategoryofweldedjointtobetestedinastatedlengthofweldoradesignatedsegmentofweldshallbeincludedintheinformationfurnishedtothebidders.Eachspottestshallcoveratleast4in.100mmoftheweldlength.当规定作抽检时，必须在提供给投标者的资料中包括下述要求：在焊缝的规定长度内或者标明的一段焊缝上，每一标明范围的待检测焊接接头上确定检测部位数目。每一抽检部位必须至少包括4in.100mm长的焊缝,PartDNDTProcedures,AWSD1.1,6.15.3SpotTesting.抽检Whenspottestingrevealsindicationsofunacceptablediscontinuitiesthatrequirerepair,theextentofthosediscontinuitiesshallbeexplored.Twoadditionalspotsinthesamesegmentofweldjointshallbetakenatlocationsawayfromtheoriginalspot.ThelocationoftheadditionalspotsshallbeagreeduponbetweentheContractorandtheverificationInspector.当抽检显示有需作返修的不合格不连续性时，必须仔细检查这些不连续性的范围。还必须在离开原抽检不合格的部位的相同焊段上另处增加2个抽检部位。增加的抽检位置必须由承包商和监造检验员共同商定。,PartDNDTProcedures,AWSD1.1,PartDNDTProcedures,6.15.4RelevantInformation.NDTpersonnelshall,priortotesting,befurnishedorhaveaccesstorelevantinformationregardingweldjointgeometries,materialthicknesses,andweldingprocessesusedinmakingtheweldment.NDTpersonnelshallbeapprisedofanysubsequentrepairstotheweld.在作检测前，必须向NDT人员提供、或使他们有途径得到有关焊缝接头的几何形状、材料厚度和用以制作该焊件的焊接方法等相关资料。并必须向NDT人员通报任何后续的焊缝返修的情况。,AWSD1.1,PartDNDTProcedures,Wheneitherofthetwoadditionalspotsshowdefectsthatrequirerepair,theentiresegmentofweldrepresentedbytheoriginalspotshallbecompletelytested.Iftheweldinvolvesmorethanonesegment,twoadditionalspotsineachsegmentshallbetestedatlocationsagreeduponbytheContractorandtheverificationInspector,subjecttotheforegoinginterpretation.如果增加的两抽检部位中有一个显示有需要返修的缺陷，则必须对原抽检部位所代表的整个焊段进行检测。如焊缝包括一个以上的焊段，则必须对每一焊段增加二个抽检部位进行检测，其位置亦由承包商与监造检验员商定，并按上述说明处理,AWSD1.1,PartERadiographicTesting(RT),ASTME94：StandardRecommendedPracticeforRadiographicTesting(射线检测推荐标准方法)ASTME142：StandardMethodforControllingQualityofRadiographicTesting,(射线检测质量控制标准方法)ASTME747：ControllingQualityofRadiographicTestingUsingWirePenetrameters,(使用线型像质计的射线检测质量控制)ASTME1032：RadiographicExaminationofWeldments.(焊件的射线检测),6.17RTProcedures,6.17.3RemovalofReinforcement.6.17.3.1Tabs(引弧板).WeldtabsshallberemovedpriortoRTunlessotherwiseapprovedbytheEngineer.除非工程师同意，否则焊缝引、熄弧板必须在射线照相检测前除去6.17.3.2SteelBacking(衬垫).Whenrequiredby5.10orotherprovisionsofthecontractdocuments,steelbackingshallberemoved,andthesurfaceshallbefinishedflushbygrindingpriortoRT.Grindingshallbeasdescribedin5.24.3.1.5.10或合同文本的其他条款要求使用的钢衬垫必须除去，表面必须在射线照相前打磨齐平。打磨必须按5.24.4.1所述要求。,6.17.3.3Reinforcement.Whenweldreinforcementorbacking,orboth,isnotremoved,orwireIQIalternateplacementisnotused,steelshimswhichextendatleast1/8in.3mmbeyondthreesidesoftherequiredholetypeIQIorwireIQIshallbeplacedunderthehole-typeIQIorwireIQI,sothatthetotalthicknessofsteelbetweenthehole-typeIQIandthefilmisapproximatelyequaltotheaveragethicknessoftheweldmeasuredthroughitsreinforcementandbacking.当焊缝余高、或衬垫、或两者都不除去时，或线型像质计不以另外的方式放置，则必须在孔型像质计或线型像质计下放置钢质补偿垫片，使得孔型像质计与底片之间的钢质被偿垫片的总厚度大致等于包括余高和衬垫板厚度在内的焊缝的平均厚度，补偿垫片至少要比所用孔型像质计或线型像质计的三个边超出1/8in.3mm,6.17.4RadiographicFilm.RadiographicfilmshallbeasdescribedinASTME94.LeadfoilscreensshallbeusedasdescribedinASTME94.Fluorescentscreensshallbeprohibited.射线照相胶片必须符合ASTME94所述要求。必须按ASTME94所述使用铅箔增感屏，严禁用萤光增感屏,6.17.5Technique.6.17.5.1GeometricUnsharpness.(几何不清晰度)Gammaraysources,regardlessofsize,shallbecapableofmeetingthegeometricunsharpnesslimitationofASMEBoilerandPressureVesselCode,SectionV,Article2.6.17.5.2Source-to-SubjectDistance.(射线源至工件的距离)Thesourceto-subjectdistanceshallnotbelessthanthetotallengthoffilmbeingexposedinasingleplane.放射源至工件的距离严禁小于在单平面上曝光的底片总长度。,6.17.5.3Source-to-SubjectDistanceLimitations.射线源至工件距离的限制Thesource-to-subjectdistanceshallnotbelessthanseventimesthethicknessofweldplusreinforcementandbacking,ifany,norsuchthattheinspectingradiationshallpenetrateanyportionoftheweldrepresentedintheradiographatananglegreaterthan26-1/2fromalinenormaltotheweldsurface.放射源至工件的距离严禁小于焊缝厚度加上余高和衬垫的7倍，且穿透被检验焊缝的射线与焊缝表面的垂线所成角度严禁大于26.5。,6.17.7IQISelectionandPlacement.,6.17.8Technique.6.17.8.1FilmLength.(胶片长度)Filmshallhavesufficientlengthandshallbeplacedtoprovideatleast1/2in.12mmoffilmbeyondtheprojectededgeoftheweld.胶片必须有足够长度，并且其放置必须超出焊缝投影边至少1/2in.12mm,6.17.8.2OverlappingFilm.(胶片搭接)Weldslongerthan14in.350mmmayberadiographedbyoverlappingfilmcassettesandmakingasingleexposure,orbyusingsinglefilmcassettesandmakingseparateexposures.Theprovisionsof6.17.5shallapply长度超过14in.350mm的焊缝的射线照相，可以将底片暗盒搭接起来作一次曝光，或用单个底片暗盒分别曝光。必须符合6.17.5的要求。,6.17.8.3Backscatter.(背散射)Tocheckforbackscatterradiation,aleadsymbol“B,”1/2in.12mmhigh,1/16in.2mmthickshallbeattachedtothebackofeachfilmcassette.Ifthe“B”imageappearsontheradiograph,theradiographshallbeconsideredunacceptable.为检测背散射，应将一个高12mm，厚2mm的铅字“B”放在每一底片暗盒的背面。如在射线底片上出现“B”的图像，则应判定射线底片不合格。,6.17.9FilmWidth.Filmwidthsshallbesufficienttodepictallportionsoftheweldjoint,includingtheHAZs,andshallprovidesufficientadditionalspacefortherequiredhole-typeIQIsorwireIQIandfilmidentificationwithoutinfringingupontheareaofinterestintheradiograph.底片应有足够的宽度，以拍摄包括热影响区在内的焊接接头的所有部分，且应另外有足够的地方放置所需的孔型或线型像质计及底片记号。,6.17.10QualityofRadiographs.Allradiographsshallbefreefrommechanical,chemical,orotherblemishestotheextentthattheycannotmaskorbeconfusedwiththeimageofanydiscontinuityintheareaofinterestintheradiograph.Suchblemishesinclude,butarenotlimitedtothefollowing:(1)fogging灰雾(2)processingdefectssuchasstreaks,watermarks,orchemicalstains诸如条纹、水迹或化学污染等处理过程的缺陷,(3)scratches,fingermarks,crimps,dirtiness,staticmarks,smudges,ortears划痕、指印、皱纹、污迹、静电击痕、斑痕或撕裂(4)lossofdetailduetopoorscreen-to-filmcontact因增感屏与底片不够密贴而导致的不清晰(5)falseindicationsduetodefectivescreensorinternalfaults因增感屏不良或内在毛病而造成虚假显示,6.17.11DensityLimitations.Thetransmittedfilmdensitythroughtheradiographicimageofthebodyoftherequiredhole-typeIQI(s)andtheareaofinterestshallbe1.8minimumforsinglefilmviewingforradiographsmadewithanX-raysourceand2.0minimumforradiographsmadewithagamma-raysource.Forcompositeviewingofdoublefilmexposures,theminimumdensityshallbe2.6.Eachradiographofacompositesetshallhaveaminimumdensityof1.3.Themaximumdensityshallbe4.0foreithersingleorcompositeviewing.对于单一胶片成像，光线投射胶片上所置孔型像质计和检验部位图像时，如采用X射线源，则最小黑度应为1.8，如采用的是射线源，最小黑度应为2.0.对于双片曝光的检验，最小黑度应为2.6.复合组的每一射线照相底片的最小黑度应为1.3.不论是单片检视还是复合检视，最大黑度都应为4.0.,6.17.11.1H&DDensity.ThedensitymeasuredshallbeH&Ddensity(radiographicdensity),whichisameasureoffilmblackening,expressedas:D=logIo/Iwhere:D=H&D(radiographic)densityH&D黑度Io=lightintensityonthefilm,and入射底片的光强度I=lighttransmittedthroughthefilm.透射过底片的光强度,6.17.11.2Transitions.过渡Whenweldtransitionsinthicknessareradiographedandtheratioofthethicknessofthethickersectiontothethicknessofthethinnersectionis3orgreater,radiographsshouldbeexposedtoproducesinglefilmdensitiesof3.0to4.0inthethinnersection.Whenthisisdone,theminimumdensityrequirementsof6.17.11shallbewaivedunlessotherwiseprovidedinthecontractdocuments.当对焊缝厚度过渡区位置进行射线照相、且较厚件厚度与较薄件厚度之比等于或大于3时，曝光的射线照相的胶片，在单底片上较薄截面处的黑度应为3.04.0。当做到这一点时，则必须放弃6.17.11的最小黑度要求，除非合同文本上另有规定。,6.18SupplementaryRTRequirementsforTubularConnections管材连接RT补充要求Thetechniqueusedtoradiographcircumferentialbuttjointsshallbecapableofcoveringtheentirecircumference.Thetechniqueshallpreferablybesingle-wallexposure/single-wallview.Whereaccessibilityorpipesizeprohibitsthis,thetechniquemaybedouble-wallexposure/single-wallviewordouble-wallexposure/double-wallview.,6.18.1.1Single-WallExposure/Single-WallView.单壁单影,6.18.1.2Double-WallExposure/Single-WallView.双壁单影,6.18.1.3Double-WallExposure/Double-WallView.双壁双影,RTAcceptanceCriteria,WeldsshownbyRTthatdonotmeettherequirementsofPartC,oralternateacceptancecriteriaper6.8,shallberepairedinconformancewith5.26.Discontinuitiesotherthancracksshallbeevaluatedonthebasisofbeingeitherelongatedorrounded.Regardlessofthetypeofdiscontinuity,anelongateddiscontinuityshallbedefinedasoneinwhichitslengthexceedsthreetimesitswidth.Aroundeddiscontinuityshallbedefinedasoneinwhichitslengthisthreetimesitswidthorlessandmayberoundorirregularandmayhavetails.经射线