简介:Asameansofsurfacemodificationprocess,metalsurfacenanocrystallization(MSN)hasattractedwidespreadattentionandenjoyedagreatprospect.However,currentlylittleresearchiscarriedoutregardingMSNofweldedjoint.Theprocessesofhighenergyshotpeening(HESP)technologyandultrasonicimpacttreatment(UIT)werecarriedouttoachievejointsurfacenanocrystallization.ThegrainsizeofbeforeandaftertheweldedjointsurfacenanocrystallizationwerecomparativelyanalyzedwithX-raydiffractometer,thesurfacedeformationlayerthicknessofbeforeandaftertheweldedjointsurfacenanocrystallizationwerecomparativelyanalyzedwithopticalmicroscopy,thesurfacehardnessofbeforeandaftertheweldedjointsurfacenanocrystallizationwerecomparativelyanalyzedwithmicrohardnessmachine.TheresultsshowthatbothoftheprocessescanachieveweldedjointsurfacenanocrystallizationandtheweldafterHESPhavesmallergrainsize,largerdeformationlayerthicknessandhigherhardnessvaluesthanthoseafterUIT.However,HESPisrestrainedbytheshapesandsizesofweldingmaterials,sotheUITprocessispreferredtouseinthegeneralengineeringpracticalapplications.
简介:Vibrationfatigueisthemainfailuremodeofcompressorblade.Evaluatingthevibrationstressofbladethatleadstocrackingisveryusefulforanalysisofvibrationfatigue.Inthispaper,fatiguestressestimationmethodsbyquantitativefractographywerestudiedthroughexperimentalbladeandin-servicefirst-stagecompressorbladeinordertoevaluatetheinitiationvibrationstressofin-serviceblade.Theanalysisprocessofinitiationvibrationstresswasestablished.Theevaluatingresultofvibrationstressofin-servicebladesubjectedtocentrifugalforceandbendingvibrationstressagreeswithaeroenginetestresult.Itisshownthattheevaluationmethodcannotonlyevaluatetheequivalentfatiguestressesofdifferentcrackdepthsbutalsoyieldtheinitiationequivalentfatiguestress.
简介:克瑞能源流体解决方案公司(CraneEnergyFlowSolutions)已购买了科隆巴赫集团的全部股本。基于德国Kreuztal的该公司全球有640名雇员,2008年的销售额估计九千一百万美元。收购包括在斯洛文尼亚的制造和铸造厂和在中国的一个合资公司的所有权。