无损检测UT工艺规程

文件编号厦门船舶重工股份有限公司第A/0版质量与职业健康安全管理体系XSI/QMD-NDT-UT-01探伤室-无损检测（UT）工艺规程共22页无损检测（UT）工艺规程RegulationOfUltrasonicTesting修改记录栏修改人审核人生效标记处数修改依据日期日期日期姓名日期姓名日期编制审定审核批准2012年6月1日起实施无损检测（UT）工艺规程RegulationOfUltrasonicTesting目录List1主内容Thesubjectcontent............................22适用范围Applicationscope..............................23参考文件Referencedocuments...........................24人员资格Personnelqualification..........................35设备要求Equipmentrequirements........................36探头Probe...........................................47试块Testblock........................................48设备仪器校验Instrumentcalibrationofequipments.........69探头校准和耦合剂Probecalibrationandcoupling...........610距离-波幅曲线（DAC曲线）DistanceAmplitudeCurve......611校验与复核Verifyingandrechecking.....................812检测程序Testingprocedures............................913评定Assessing.......................................1714记录Records........................................1915报告Report.........................................19附录Appendix......................................191主题内容Thesubjectcontent本工艺流程规定了本司船舶产品超声检测的一般要求、技术等级、工艺文件、检测实施和焊缝质量分级等。Thisregulationprovidesthegeneralrequirements,technicallevels,processdocuments,testimplementationandweldingqualityclassificationofultrasonictestingonourcompany.2适用范围Applicationscope本工艺流程适用于本司造船、修船及非船产品零部件母材厚度为（8～150）mm铁素体钢全熔焊透缝A型脉冲反射式手工接触的超声波检测；不适用于铸钢及奥氏体钢焊缝，外径<250mm和内外径之比<70%的纵向焊缝；外径小于200mm的筒体周向焊缝、各种尺寸曲面相贯焊缝。ThisregulationisapplicabletoAtypepulsereflectiontypeofmanualcontactultrasonictestingfor8～150mmthicknessofferritesteelcompletefusionweldingonourcompany’sshipbuilding,repairingandpartsofno-marineproducts.Noapplicabletocaststeelandausteniticsteelwelds,longitudinalweldofouterdiameterlessthan250mmandtheinnerandouterdiameterratiolessthan70%,columnringweldofoutsidediameterlessthan200mm;varioussizeofbendsurfacejoiningwelds.3参考文件Referencedocuments3.1JB/T4730-2005《压力容器无损检测》超声波检测部分；3.1JB/T4730-2005Theultrasonicdetectionpartof"nondestructivetestingofpressurevessels".3.2中国船级社无损检测超声检测3.2TheultrasonictextbookcompiledbyCCS.3.3JB4126《超声检测用钢质试块的制造和控制》3.3JB4126"Themanufactureandcontrolofsteeltestpieceforultrasonictesting".3.4ZBJ04001《A型脉冲反射式超声波探伤系统工作性能测试》3.4ZBJ04001"TheperformancetestmethodsofAtypepulsereflectionultrasonicflawdetectionsystem".3.5ZBY230《A型脉冲反射式超声波探伤仪通用技术条件》3.5ZBY230"GeneraltechnicalconditionsofAtypepulsereflectionultrasonictestinginstrument".3.6ZBY232《超声波探伤用1号试块技术条件》3.6ZBY232"Technicalconditionsof1typestandardtestpieceforultrasonictesting".3.7ZBY231《超声波探伤用探头性能测试方法》3.7ZBY231"Theperformancetestmethodsofprobeforultrasonicinspection".3.8CB/T3959-2011《船舶钢焊缝超声波检测工艺和质量分级》3.8CB/T3959-2011"Technologyandqualityclassificationofultrasonictestinginshipsteelweld".3.9DNV入级指导No.7中超声检测部分3.9TheultrasonicdetectionpartofjoiningDNVdirectionNo.7.3.10CTS-4020数字式超声波探伤仪使用说明书3.10ThedirectionofCTS-4020digitalultrasonictestinginstrument.4人员资格Personnelqualification4.1从事无损检测的人员必须经过专业技术培训，并按照中国船级社《无损检测人员资格鉴定与认证规范》进行资格考核，取得资格证书后只能从事与其证书所注明的方法与级别相适应的无损检测工作；4.1TheNDTpersonnelmustthroughprofessionaltechnicaltrainingandqualificationexaminationaccordingtotheCCS"nondestructivetestingpersonnelqualificationandcertificationstandard”,andonlycandealwiththenondestructivetestingworkadapttothemethodandlevelindicatedinqualificationcertificate.4.2Ⅰ级人员可在Ⅱ、Ⅲ级人员指导下进行无损检测操作，记录检测数据，整理检测资料；4.2Ⅰlevelpersonnelcannondestructivetestingoperation,recordtestdata,establishinspectiondocumentsunderguidanceofⅡ,Ⅲlevelpersonnel.4.3Ⅱ级人员可编制一般的无损检测程序，按照无损检测工艺规程或在Ⅲ级人员指导下编写工艺卡，并按无损检测工艺独立进行检测操作，评定检测结果，签发检测报告；4.3Ⅱlevelpersonnelcancompiletheordinarytestingproceduresofthenondestructivetesting,accordingtonondestructivetestingprocedureorundertheguidanceofⅢlevelpersonneltowritetheprocesscard,andindependenttestaccordingtonondestructivetestingregulation,assessthetestresults,andissuethetestreport.4.4Ⅲ级人员可根据标准编制无损检测工艺，审核或签发检测报告，协调Ⅱ级人员对检测结论的技术争议。4.4.Ⅲlevelpersonnelcancompilethenondestructivetestingproceduresaccordingtostandard,revieworissueinspectionreport,harmonizethetestresultsdisputefromⅡlevelpersonnel.5设备要求Equipmentrequirements5.1现使用的仪器见表15.1Nowusingequipmentsseetable1.5.2仪器的工作频率范围一般为0.5~10MHz。5.2Theoperatingfrequencyrangeofinstrumentgeneralis0.5~10MHz.5.3仪器和探头的组合灵敏度：在达到所检工件最大声程时，其灵敏度余量应不小于10dB，且电噪声电平不大于垂直满刻度的20%。5.3Combinationsensitivityofinstrumentandprobe:Reachingthemaximumbeampathofworkpiece,thesurplussensitivityshallbenotlessthan10dB,andelectricalnoiselevelisnotgreaterthan20%ofverticalfullscale.5.4衰减器精度：总增益量不小于80db，最小步进每档不大于2db；任意相邻12dB误差在±1dB以内，最大累计误差不超过1dB。5.4Attenuatoraccuracy:thetotalplusamountisnotlessthan80dB,thesmalleststepisnotmorethan2dB;anyadjacent12dBerrorislessthan±1dB,maximumaccumulatederrorisnotmorethan1dB.5.5水平线性：水平线性误差不大于1%。5.5Horizontallinearity:horizontallinearityisnotmorethan1%.5.6垂直线性：在荧光屏满刻度的80%范围内呈线性显示；垂直线性误差不大于5%。5.6Verticallinearity:lineardisplayedin80%offullscreen;verticallinearityisnotmorethan5%.表1：Table1制造厂型号名称汕头CTS-4020数字超声波探伤仪汕头CTS-2000PL数字超声波探伤仪友联PXUT-U1数字超声波探伤仪6探头Probe6.1晶片有效面积除另有规定外一般不应超过500mm²，且任意一边长不大于25mm。6.1Waferareaunlessotherwisespecifiedgeneralshouldnotexceed500mm²,andanysidelengthisnotmorethan25mm.6.2单斜探头声束轴线水平偏离角不应大于2°，主声束垂直主方向不应有明显的双峰。6.2.Thebeamaxishorizontaldeviationangleofsingleobliqueprobeshouldnotexceed2°,themainperpendiculardirectionofmainbeamshouldnothaveobviousdoublewavecrests.6.3直探头的远场分辨力应大于或等于26dB，斜探头的远场分辨力应大于或等于6dB。6.3Thefarfielddifferentiationabilityofstraightprobeshouldnolessthan26dB,obliqueprobeshouldnolessthan6dB.6.4仪器和探头的系统性能应按JB/T9214的规定进行测试。6.4ThesystemperformanceofinstrumentanddetectorshallbetestedaccordingtotheprovisionsofJB/T9214.7试块Testblock7.1试块应采用与被检工件相同或近似声学性能的材料制成，该材料用直探头检测时，不得有大于Φ2mm平底孔当量直径的缺陷。7.1Testblockshallbemadebythematerialwithsameorsimilaracousticcapabilitytotheinspectedworkpiece,whenthismaterialtestedwithstraightprobe,thereshallnothavedefectsthatequivalentdiameterofflat-bottomedholelargerthanΦ2mm.7.2试块的制造要求应符合ZBY232和JB4126的规定。7.2TheproductionrequirementsoftestblockshallbeinaccordancewiththerulesofZBY232andJB4126.7.3现场检测时，也可采用其它型式的等效试块7.3Atfielddetection,canalsouseothertypesofequivalenttestblocks.7.4采用的标准试块为IIW或CSK－ⅠA.其中CSK－ⅠA标准试块其形状和尺寸如图1。7.4ThestandardtestblockisIIWorCSK-ⅠA.TheshapeandsizeofCSK-ⅠAstandardtestblockisshowninfigure1.图1CSK-IA试块Figure1TestblockofCSK-IA7.5对比试块分别为CTRB-1，CTRB-2，CTRB-3三种形式，其中CTRB－2型的形状、尺寸如图2所示7.5ThecontrasttestblocksarethreetypesofCTRB-1,CTRB-2,CTRB-3.TheshapeandsizeofCTRB-2isshowninFigure2图2CTRB－2试块Figure2CTRB－27.6检测曲面工件时，如检测面曲率半径R小于等于W²/4（W为探头接触面宽度，环缝检测时为探头宽度，纵缝检测时为探头长度）时，应采用与检测面曲率相同的对比试块。一个对比试块可检其直径0.9～1.5倍的工件。7.6Wheninspectingcurvedsurfaceworkpiece,ifthecurvatureradiusRofdetectionsurfaceisnotmorethanW²/4(Wisprobecontactsurfacewidth,asprobewidthinringseamtesting,probelengthinlongitudinalseamtesting),shouldusingthecontrasttestblockwiththesamecurvatureradius.Acontrasttestblockcanchecktheworkpieceswith0.9~1.5timesdiameter.8设备仪器校验Instrumentcalibrationofequipments在仪器开始使用时，应对仪器的水平线性进行测定，测定方法按ZBY230的规定进行。在使用过程中，仪器维修后及每隔三个月至少应对仪器的水平线和垂直线性进行一次校准。AccordingtotheprovisionsofZBY230,thehorizontallinearityshouldbemensuratedbeforeusingtheequipment.Duringusingtime,afterrepairedoreverythreemonthsshouldcalibratethehorizontalandverticallinearityforonetimeatleast.9探头校准和耦合剂Probecalibrationandcoupling在探头开始使用时，应对探头进行一次全面的性能校准。测定方法应按ZBY231的有关规定进行。Beforeusingtheprobe,shouldhaveacomprehensiveperformancecalibration.ThecalibrationmethodshouldbeaccordingtotherelevantprovisionsofZBY231.9.1斜探头校准Calibrationofobliqueprobe使用前，斜探头至少应进行前沿距离、K值、主声束偏离、灵敏度余量和分辨力等的校准。使用过程中，每个工作日应校准前沿距离、K值和主声束偏离。Beforeuse,obliqueprobeshouldbecalibratedatleastforforwarddistance,Kvalue,mainbeamdeviation,surplussensitivityanddifferentiationability.Attheusingtime,eachworkdayshouldbecalibratedforwarddistance,Kvalueandmainbeamdeviation.9.2直探头校准Calibrationofstraightprobe直探头的灵敏度余量和分辨力应每隔一个月检查一次。Thesurplussensitivityanddifferentiationabilityofstraightprobeshouldbeinspectedonetimeforeverymonth.9.3耦合剂应具有良好的透声性能和适当的粘度，并对被检工件和人体无害，检测后容易清洗。甘油、75%以上甘油溶液、水、机油、浆糊或相似声阻抗的液体均可作为耦合剂。9.3Thecouplingshouldhavegoodsoundtransmissionperformanceandproperviscosity,andharmlesstotheinspectedworkpieceandhumanbody,easycleaningafterdetection.Glycerol,morethan75%glycerolsolution,water,oil,pasteorsimilaracousticimpedanceoftheliquidcanbeusedascouplingagent.10距离-波幅曲线（DAC曲线）DistanceAmplitudeCurve10.1距离一波幅曲线的绘制10.1Distanceamplitudecurvedrawing10.2距离一波幅曲线按所用探头和仪器在试块上实测的数据绘制而成，曲线的制作方法见超声波探伤仪使用说明书。该曲线族由评定线、定量线和判废线组成，评定线与定量线之间（包括评定线）为Ⅰ区，定量线与判废线之间（包括定量线）为Ⅱ区，判废线及其以上区为Ⅲ区。如图4所示。10.2DACdrawingaccordingtothedataoftheprobeandinstrumenttestinginthetestblock.ThemethodsofDACdrawingisshownintheusinginstructorofultrasonicflawdetector.Thefamilyofcurvesmakeupofevaluatingline,quantitativelineandsentencedwasteline,theareabetweenquantitativeandevaluationlines(includingevaluatingline)callforⅠregion,betweenquantitativeandsentencedwasteline(includingquantitativeline)callforIIregion,sentencedwastelineandabovecallforⅢregion.Asshowninfigure4.10.3距离一波幅曲线的灵敏度选择10.3TheselectionofDACsensitivity.10.3.1根据被检焊缝母材厚度不同，其距离一波幅曲线灵敏度按表2的规定。10.3.1Accordingtothedifferentparentmetalthicknessofdetectedwelds,theDACsensitivityisshownintable2.10.3.2直探头的距离一波幅曲线灵敏度按表3的规定。距离一波幅曲线的制作可在CS2试块上进行。10.3.2TheDACsensitivityofstraightprobeisshownintable3.DistanceamplitudecurvecanbemadeonCS2testblock.10.3.3检测横向缺陷时，应将各线灵敏度均提高6dB。10.3.3Forthedetectionoftransversedefects,eachline’ssensitivityshouldenhanced6dB.10.3.4检测面曲率半径R小于或等于W²/4时，距离一波幅曲线的绘制应在曲面对比试块上进行。10.3.4WhenthecurvatureradiusRofdetectionsurfaceisnotmorethanW²/4,distanceamplitudecurveshouldbemadeonthecontrasttestblockofcurlysurface.图4距离—波幅曲线Figure4thedistanceamplitudecurve10.3.5工件的表面耦合损失的材质衰减应与试块相同。10.3.5Thelossofmaterialattenuationonworkpiecesurfacecouplingshouldbesametotestblocks.10.3.6扫查灵敏度不低于最大声程处的评定线灵敏度。10.3.6Thescanningsensitivityisnotlessthanevaluationlinesensitivityatthemaximumsounddistance.表2距离一波幅曲线的灵敏度Table2theDACsensitivity板厚mm评定线测长线判废线≤50φ3－16dBφ3－10dBφ3＞50～100φ3－12dBφ3－6dBφ3+2dB＞100φ3－8dBφ3－2φ3+2dB表3T型焊接接头直探头距离一波幅曲线的灵敏度Table3TheDACsensitivityofstraightprobeonTweldedjoint评定线定量线判废线φ2mm平底孔φ3mm平底孔φ4mm平底孔11校验与复核Verifyingandrechecking11.1每次检测开始前，应对仪器的水平线性和检测灵敏度进行校验。11.1Beforetesting,thehorizontallinearityanddetectionsensitivityofinstrumentshouldbeverified.11.2在检测过程中，出现下列请况时，应对检测系统进行校验：11.2Intheprocessoftesting,whenthefollowingsituationsappear,thedetectionsystemshouldbeverified.①校准后的探头、耦合剂和仪器调节旋钮发生改变时；①Whentheverifiedprobe,couplingmatterandadjustingknobofapparatushavechange;②检测人员怀疑水平线性或者扫查灵敏度有变化时；②Whentheinspectionpersonnelsuspectedofhorizontallinearorscanningsensitivityhavechange;③检测系统连续工作4h以上时；③Whenthedetectionsystemcontinuouslyoperatingabove4H;11.3检测结束前，应对检测系统复核。11.3Beforetheendingofdetection,thedetectionsystemshouldberechecked.11.3.1时基线的复核Recheckingoftimebaseline每次检测结束前，应对时基线进行复核。如果时基线上任意一点的偏移超过时基线的10%，则应重新调节时基线，并对上一次复核以来所有的检测部位进行重新检测。Beforeendingofeachinspection,thetimebaselineshouldberechecked.Iftheoffsetofanypointonthetimebaselinemorethan10%ofthebaseline,thetimebaselineshouldbereadjusted,andallthedetectedpositionduringthelasttimeofrecheckingshouldbeafreshinspected.11.3.2检测灵敏度（DAC曲线）的复核Recheckingofinspectionsensitivity(DAC)每次检测结束前，应对检测灵敏度（DAC曲线）进行复核。对DAC曲线）的复核不少于3点。如曲线上任何一点幅度下降2dB或2dB以上，则应对上一次复核以来所有的检测部位进行重新检测；如幅度上升2dB或2dB以上，则应对所有的检测记录进行重新评定。Beforeendingofeachinspection,theinspectionsensitivity(DAC)shouldberechecked.TherecheckingofDACnotlessthan3points.Iftheamplitudeofanypointonthecurvedrop2dBor2dBabove,allthedetectedpositionduringthelasttimeofrecheckingshouldbeafreshinspected;Iftheamplitudeascend2dBor2dBabove,allthedetectedrecordsshouldbeafreshassessed.11.4在对检测系统进行校准、复核和线性测定时，任何影响仪器线性的控制器（如抑制或滤波开关等）应处于关闭状态或最低水平位置。11.4Duringthetimeofverifying,recheckingandlinearitymensurationofthedetectingsystem,anycontrollerthatinfluencesthelinearityoftheinstrument(e.g.inhibitionorfilterswitchetc.)shouldbeclosedorattheminimumlevelposition.12检测程序Testingprocedures12.1检测前的准备Preparationoftest12.1.1检测时机Detectiontime一般材料焊缝冷却至室温后方可进行检测；有产生延迟裂纹倾向的材料，应在焊接完成至少24h后进行检测；有热处理要求的工件，应在热处理完成后检查。超声检测前，焊缝表面及热影响区应经外观检验合格。Whenthegeneralmaterialweldcoolingtoroomtemperaturecanbedetected;materialhavetrendofdelayedcracks,shouldbetestedatleast24haftercompletedwelding;theworkpiecehaveheattreatmentrequirements,shouldbetestedaftertheheattreatment.Beforeultrasonictesting,surfaceofweldandheataffectedzoneshallbecheckedoutbyvisualinspection.12.1.2检测面Inspectionsurface⑴检测区域的宽度包括焊缝本身，再加上焊缝两侧各相当于母材厚度30%的一段区域，这个区域最小为5mm，最大为10mm。⑴Thedetectionregionincludethewidthofweldandplus30%ofbasematerialthicknessonbothsidesoftheweld,theminimumis5mm,themaximumis10mm.⑵检测表面应平整光滑，焊接飞溅、铁屑、油垢、锈、马脚应清除干净，便于探头的自由扫查，其表面粗糙度Ra不应大于6.3μm，一般应进行打磨。⑵Thedetectionofsurfaceshouldbesmooth,weldingspatter,scrapiron,oil,rust,theweldfeetshouldbecleaned,convenientforfreescanningofprobe,thesurfaceroughnessRashouldnotlargerthan6.3μm,generallyshouldbepolished.①采用一次反射法检测时，探头移动区应不小于1.25P，P＝2TK；式中：P―跨距，mm；T―母材厚度，mm；K―探头K值；①Usingareflextesting,theprobemovementareashallbenotlessthan1.25P,P=2TK;Intype:P-span,mm;T-basematerialthickness,mm;K-Kvalueofprobe;②采用直射法检测时，探头移动区应不小于0.75P。②Usingstraighttransmittesting,theprobemovementareashallbenotlessthan0.75P.⑶去除余高的焊缝，应将余高打磨到与母材平齐；保留余高的焊缝，如果焊缝表面有咬边，较大的隆起和凹陷等也应进行适当的修磨，并作圆滑过渡，以免影响检验结果的评定。⑶Theremovalofresidualhighweld,theresidualhighshouldburnishedtoequaltobasematerial;Thepreservingresidualhighweld,iftheweldsurfacehavingundercut,largeapophysisandhollowshouldalsobeappropriateburnished,andmadeasmoothtransition,soasnottoaffecttheassessmentresults.12.1.3根据工件的检验要求，选用仪器、探头和试块。12.1.3Accordingtotheworkpiece’sinspectionrequirements,selectionofinstrument,probeandtestpiece.12.1.4仪器、探头的测试校验。12.1.4Testverifyingofinstrumentandprobe.12.1.5距离-波幅曲线的制作。12.1.5Executionofdistanceamplitudecurve.12.2耦合剂Couplingmatter采用机油、浆糊、甘油、浆糊和水等透声性好，且不损伤检测表面的耦合剂。Usingthecouplingmatterwithgoodsoundpenetrationandharmlesstothesurfaceasoil,glycerin,paste,pasteandwateretc.12.3探测频率和探头K值的选择12.3SelectionofdetectionfrequencyandprobeKvalue12.3．1探测频率的选择按表4进行选择12.3.1Selectionofdetectionfrequencyisaccordingtotable4.表4探测频率的选择Table4Selectionofdetectionfrequency母材厚度（mm）探测频率MHz≤202.5~5＞20~752~5>752~412.3.2探头K值的选择SelectionofprobeKvalue探头K值的选择应能使主声束覆盖整个焊缝检测区,条件允许时，应尽量采用较大K值探头。TheprobeKvalueshouldbeselectedtomakethemainbeamofsoundtocoverthewholeweldinspectionarea,whenconditionspermit,shouldasfaraspossibleusinglargerKprobe.条件允许时，T接头焊缝检测应分别使用直探头和斜探头扫查。Whenconditionspermit,straightandobliqueprobeshouldbeusedseparatelyinTjointweldinspection.⑴平板对接焊缝斜探头K值的选择按表5进行选择；⑴TheselectionofKvalueofobliqueprobeinplatebuttweldinspectionisshownintable5.⑵T接头焊缝斜探头K值的选择按表6进行选择。⑵TheselectionofKvalueofobliqueprobeinTjointweldinspectionisshownintable6.12.4检测覆盖率Coveragerateofdetection检测时，探头的每次扫查覆盖率应大于探头直径的10%。Eachscanningcoveragerateshouldbemorethan10%ofthediameterofprobeininspection.12.5探头的移动速度Probe’smovingspeed探头的扫查速度不应超过150mm/s。当采用自动报警装置扫查时，不受此限。Theprobe’sscanningspeedshouldnotexceed150mm/s.Whenuseautomaticalarmdevicetoscan,isnotsubjecttothisrestriction.12.6扫查灵敏度Scanningsensitivity扫查灵敏度至少比基准灵敏度高6dB。Scanningsensitivityis6dBhigherthanthebaselinesensitivityatleast.12.7母材的检验Basematerialinspection斜探头扫查声束通过的母材区域，应先用直探头检测，以便检测是否有影响斜探头检测结果的分层或其它种类缺陷存在。母村检测的规程要点如下：Thebasematerialareathatobliqueprobe’sscanningacousticbeampassthrough,shouldbeinspectedbystraightprobe,inordertodetectwhethertherehavestratificationorothertypesofdefectsthatinfluencetheobliqueprobetestresults.Thestandardsgistsofbasematerialinspectionareshownasfollows:表5平板对接焊缝斜探头K值的选择Table5TheselectionofKvalueofobliqueprobeinplatebuttweldinspection.表6T接头焊缝斜探头K值的选择Table6TheselectionofKvalueofobliqueprobeinTjointweldinspection.腹板厚度（mm）探测面探测方法折射角（K值）≤20腹板单面单侧直射法和一次反射法70°（K2.5、K2.0）70°、60°（K2.5、腹板单面单侧直射法和一次反射法K2.0、K1.5）＞20~5060°、45°（K2.0、面板外单面双侧直射法K1.5、K1.0）60°、45°（K2.0、腹板单面单侧直射法和一次反射法K1.5、K1.0）＞50~10070°、60°（K2.5、面板外单面双侧直射法K2.0、K1.5）60°、45°（K2.0、腹板双面单侧直射法和一次反射法K1.5、K1.0）>10070°、60°（K2.5、面板外单面双侧直射法K2.0、K1.5）12.7.1检测板厚不大于20mm的母材，采用5MHz的双晶直探头；检测板厚大于20mm的母材，采用2-5MHz的单晶直探头。探头晶片直径为10mm-20mm。12.7.1Dual-crystalstraightprobeof5MHzisusedtoinspectbasematerialthatthicknessislessthan20mm;singlecrystalstraightprobeof2-5MHzisusedtoinspectbasematerialthatthicknessismorethan20mm.Theprobewaferdiameteris10mm-20mm.12.7.2调节时基线，至少显示两次底波。12.7.2Adjusttimebaselinetoshowtwobottomwavesatleast.12.7.3双晶直探头调节检测灵敏度，将无缺陷的一次底波调到满屏刻度的50%，再提高10dB作为检测灵敏度。12.7.3Adjusttheprimarybottomwaveofnodefectsto50%offullscreengraduation,thenimprove10dBasthedetectionsensitivityofdual-crystalstraightprobe.12.7.4单晶直探头调节灵敏度，将无缺陷处的二次底波调到满屏刻度的100%。12.7.4Adjustthesecondarybottomwaveofnodefectsto100%offullscreengraduationasthedetectionsensitivityofsinglecrystalstraightprobe.12.7.5凡缺陷信号幅度超过荧光屏满刻度20%的部位或底波消失的区域，应在工件表面作出标记，并予以记录。12.7.5Theareathatamplitudeofdefectsignalover20%offullscreengraduationorbottomwavedisappearance,shouldbemarkedonthesurfaceoftheworkpiece,andrecorded.12.8检测方法Detectionmethods12.8.1平板对接焊缝的检测Inspectionofplatebuttweld⑴为检测纵向缺陷，原则上采用一种K值探头或两种K值探头在焊缝的单面双侧进行检测。母材厚度大于100mm，采用双面双例检测，如受几何条件限制，也可在焊缝双面单侧采用两种K值探头进行检测。斜探头应垂直于焊缝中心线放置在检测面上，作锯齿形扫查，见图5。探测前后移动的范围应保证扫查到全部焊缝截面。在保持探头垂直焊缝作前后移动的同时，还应作10°～15°的左右转动。⑴Thedetectionoflongitudinaldefect,inprincipleusingaKprobeortwoKprobestoinspectonthesingleface-doublesideofweld.Basematerialthicknessislargerthan100mm,usingdoublefaces-doublesidesdetection,suchasaffectedbygeometricconstraints,canalsousingtwoKprobetoinspectonthedoublefaces-singlesideofweld.Obliqueprobeshouldbeperpendiculartothecenterlineoftheweldplacedondetectionsurface,aszigzagscan,seefigure5.Detectionareaofmovingbackandforthshallensuretoscanthewholeweldsection.Inmaintainingtheprobeverticalseamtomoveforthandback,atthesametimeshouldalsoturnaroundfor10°~15°.图5锯齿型扫查Fig5zigzagscan⑵为检测焊缝及热影响区的横向缺陷应进行平行和斜平行扫查。检测时，可在焊缝两侧边缘使探头与焊缝中心成10～20°作斜平行扫查。见图6。焊缝母材超过100mm时，应在焊缝的两面作平行扫查或采用两种K值探头（K1和K1.5或K1和K2并用）作单面两个方向的平行扫查。⑵Thedetectionofthetransversedefectsinweldandheataffectedzoneshoulduseparallelandinclinedparallelscan.Indetection,theprobemadeparallelscanin10~20°totheweldcenteronbothedgesidesofweldseam.Seefigure6.Whenbasematerialthinnessismorethan100mm,theprobemadeparallelscanondoublefaces,orusingtwoKprobe(K1andK1.5orK1andK2wereusedassingle)tomakeparallelscanintwodirectionsonsingleface.图6斜平行、平行扫查Figure6Parallelandinclinedparallelscan⑶为确定缺陷的位置、方向和形状，观察缺陷支柱波形和区分缺陷信号或伪缺陷信号，可采用前后、左右、转角、环绕等四种探头基本扫查方式，见图7⑶Fordeterminingthedefectlocation,directionandshape,theobserveddefectspillarwaveformanddistinguishedflawsignalorfalsedefectsignal,canusefourkindsofbasicscanningmethodsasforwardandback,leftandright,corner,around,seeFigure7图7四种基本扫查方法Figure7fourbasicscanningmethods12.8.2曲面工件对接焊缝的检测Detectionofbendsurfacebuttweld⑴检测面为曲面时，可尽是按平板对接焊缝的检测方法进行检测。对于受几何形状限制，无法检测的部位应予以记录。⑴Thedetectionofcurvedsurface,canusethedetectionmethodofplatebuttweld.Thedetectionsurfaceisingeometryconstraint,positionthatcannotbedetectedshouldberecorded.⑵纵缝检测时，对比试块的曲率半径与检测面曲率半径之差小于10%。⑵Inthelongitudinalseamdetection,thecurvatureradiusdifferencebetweencontrasttestblockanddetectionsurfaceislessthan10%.①根据工件的曲率和材料厚度选择探头K值，并考虑几何临界角的限制，确保声束能扫查到整个焊缝。①AccordingtothecurvatureoftheworkpieceandmaterialthicknesschoiceKvalueprobe,andconsideringtheconstraintsofgeometriccriticalangle,toensurethatsoundbeamcanscanacrosstheweld.②探头接触面修磨后，应注意探头入射点和K值的变化，并用曲线试块作实际测定。②Thecontactsurfaceofprobeaftergrinding,shouldtakeattentiontothechangeofincidencepointandKvalue,andactualmensurateincurvetestblock.③当检测面曲率半径R大于W²/4且采用平面对比试块调节仪器时，应注意到荧光屏指示的缺陷深度或水平距离与缺陷实际的径向埋藏深度或水平距离弧长的差异，必要时进行修正。③Whenthedetectingsurface’scurvatureradiusRisgreaterthanW²/4andadjustingapparatuswithplanecontrasttestblock,shouldtakeattentiontothedifferencebetweenthedepthorhorizontaldistanceofscreenindicatingdefectsandtheradialimbeddepthorarclengthofhorizontaldistanceofactualdefects,necessarycorrection.⑶环缝检测时，对比试块的曲率半径应为检测面曲率半径的0.9～1.5倍。⑶Intheringseamdetection,thecurvatureradiusofcontrasttestblockshallbe0.9~1.5timesthanthecurvatureradiusofdetectionsurface.12.8.3管座角焊缝的检测Inspectionofpipeseatfilletweld⑴一般原则Thegeneralprinciple在选择检测面和探头时应考虑到各种类型缺陷的可能性，并使声束尽可能垂直于该焊缝结构中的主要缺陷。Inthechoiceoftestingsurfaceandprobeshouldconsiderthepossibilityofvarioustypesofdefect,andmakethesoundbeampossibleperpendiculartothemaindefectsintheweldstructure.⑵检测方式Thedetectionmethods根据焊缝结构形式，管座焊缝的检测有如下五种探测方式，可选择其中一种或几种方式组合实施检测。检测方式的选择应由双方商定，并考虑主要检测对象和几何条件的限制。（图8、图9）。Accordingtotheweldstru