简介:WiththemodifiedAlmenmethod,theforminganddevelopmentprocessofresidualstressinathermalsprayedcoatinghasbeenobtained.Thetestresultsidentifythattheresidualstressinacoatingisdependoncoatingmaterialproperties,techniqueandcoatingthickness.Thepaperpaysmuchattentiontothehysteresisbetweenthecoatingtemperatureandresidualstressinthecoatingorbetweentheappliedstressandthestrainofthecoating,andconfirmsthatthefactisresultedfromthe"GasFix"characterofathermalsprayedcoating.
简介:NondestructivetestofweldresidualstressesbyacoustoelastictechniqueJiaoFujie;ZhangWenjunandYuanZhikang(ShanghaiUniversityofEngi...
简介:Thisstudydevelopedasequentialcouplingfiniteelementproceduretopredictresidualstressesofsteelpipeswithlongitudinalwela\circumferentialweldandspiralweld.Theresultsshowthattheresidualstressinheataffectedzone(HAZ)ishigherthanthatinweldforspiralweldpipe.Forthecircumferentialweldpipeandspiralweldpipe,theresidualstressininnersurfaceishigherthanthatinoutersurface.However,forthespiralweldpipe,theresidualstressininnersurfaceissmallerthanthatinoutersurface.Thehoopresidualstressofcircumferentialweldpipeishigherthanthatoflongitudinalweldpipe,whiletheaxialresidualstressofcircumferentialweldpipeissmallerthanthatoflongitudinalweldpipe.Thehoopstressesforcircumferentialweldpipeandaxialstressforlongitudinalweldpipehaveexceededtheyieldstrengthofbasemetal.Withtheincreaseofhelixangle,thehoopstressdecreaseswhiletheaxialstressincreases.Forthespiralpipe(α=30°to50°),boththehoopstressandaxialstressarerelativelysmall.Thespiralpipe(helixanglerangingfrom30°to50°)ishelpfultoreducestresscorrosioncracking(SCC)anditisrecommendedtomanufacturethesteelpipe.
简介:MagneticBarkhausennoise(MBN)isaphenomenonofelectromagneticenergyduetothemovementofmagneticdomainwallsinsideferromagneticmaterialswhentheyarelocallymagnetizedbyanalternatingmagneticfields.AccordingtoFaraday’slawofelectromagneticinduction,thenoisecanbereceivedbythecoilattachedtothesurfaceofthematerialbeingmagnetizedandthenoisecarriesthemessageofthecharacteristicsofthematerialsuchasstresses,hardness,phasecontent,etc.Basedonthecharacteristicofthenoise,researchingabouttherelationshipbetweentheresidualstressintheweldingassemblyandthenoisearecarriedout.Furthermore,dataprocessisperformedbyRMS(RootMeanSquare)equationandPowerSpectrumanalysis.
简介:Whenmeasuringresidualstressofcoarse-grainaluminumalloyusingX-raydiffractionmethod,thediffractionprofileshowstwopeaksandpositionofmeasured2dwillbechanged,whichleadtoaninaccuratemeasurementresult.Hence,inthispaper,somemethodswereemployedtoimprovethemeasurementaccuracy.Duringthemeasuringprocess,differentparameters(diameterofirradiatedarea,Ψ-oscillationrangeandexposuretime)wereselectedandprofilepeakshiftmethodwasutilized.Moreover,whenthe20ofprofileswasdetermined,differentcalculationmethodswereusedtocalculatetheresidualstress.TheresultsshowthatdiameterofirradiatedareaandΨ-oscillationrangehavesignificantinfluenceonthemeasuringresult.Forstressvaluecalculateddirectlyfromthetestequipment,crosscorrelationmethodismoreaccuratethantheabsolutepeak.Furthermore,anothertwocalculationmethodsofslopewith2θ-sin~2Ψande-sin~2Ψwereusedtocalculatethestressbasedonparameters(2θ,ε)obtainedfromcrosscorrelationmethod.Itisconcludedthat20-sin~2Ψmethodcanfurtherimprovethemeasurementaccuracy.