简介:磨擦促使处理(FSP)作为在12修理裂缝的一个方法被调查?公里厚304L不锈钢板。愈合的可行性被用一个PCBN/W-Re工具处理一个逐渐变细的裂缝与表明一25?公里直径肩膀和6.4的大头针长度?公里。实验证明愈合是可能的开始的一个裂缝狭窄然后日益增多地长大到2的宽度?公里。板实验上的祷告被用来为创造发现最好的参数一巩固与贱金属相比与坚硬差别的最少的数量搅动地区。在一些标本的谷物精炼更高导致了大部分搅动地区坚硬,与贱金属相比。谷物尺寸对microhardness的一个阴谋显示出在谷物尺寸和坚硬之间的很强壮的反的关联,从Hall-Petch关系期望。腐蚀测试被执行以便在stir地区的潜在的促进感受性上评估FSP的效果。在1000以后?在在没有腐蚀产品在基础材料控制上或在任何磨擦上形成了,这被发现的房间温度的3.5%盐溶液的断断续续的沉浸的h搅动处理标本。
简介:Achievingnotonlyhighmechanicalstrengthsbutalsohighductilityisrecentlyestablishedusinganadditivemanufacturingtechniquecalledselectivelasermelting.Inthepresentstudy,stainlesssteel304Lfullydensesamplesweresuccessfullyprintedusingthe3Dsystems-ProX300printingmachine.TheductilityandtensileyieldstrengthwerealmosttwoandthreetimeshighercomparedtothoseofASTMcast'salloy.Honeycomblikenano-cellularstructurew让hdifferentorientationwasobservedinthefinegrains(-4μm)duetofastcoolingrate.Inadd让ion,theformationofmartensitephaseinrandomgrainsisalsoacontributortothestrengths.Furthermore,negativeresidualstressesinthebuildandhorizonraldirectionsweredetectedandassistedfurtherincreaseinthetensilestrength.Fractographyrevealedtheductilefeatureofplasticdeformationandthecrackopeningsatunmeltedparticlesorpores.
简介:Twothermo-mechanicalcontrolledprocesses(TMCP)includingcontrolledrollingandacceleratedcoolingareproposedfortheproductionofheavygaugeSUS304Lausteniticstainlesssteelplateswithdifferentstrengthsandothercharacteristics.BasedontherecrystallizationmechanismandcarbideprecipitationbehaviorofSUS304Lausteniticstainlesssteel,TMCPprovidesapowerfulmeanstocontrolthemicrostructureandprecipitationofthehotrolledsteelplatebythecontrolledrollingandacceleratedcoolingprocess.Thedislocationdensityandgrainsizearethemainfactorsindeterminingthestrengthofthestainlesssteelplates.Therefore,itisnecessarytostrictlycontrolthehotrollingparameters,includingparameterssuchasthefinishhotrollingtemperatureintherecrystallizationtemperatureregionandthetotalreductioninthenon-recrystallizationregion.Furthermore,inordertoavoidcarbideprecipitationandguaranteetheintergranularcorrosionresistanceofTMCPSUS304Lausteniticstainlesssteel,acriticalcoolingrateafterrollingisdetermined.
简介:摘要:本文主要介绍了台山核电站一期工程2#机组常规岛项目高压给水系统材质为TP304L的大口径厚壁不锈钢管道在安装过程中,通过一系列严格的焊接工艺措施和焊接操作技巧,有效地保证了管道安装焊接质量,对今后类似大口径厚壁不锈钢管道的焊接可提供良好的借鉴作用。
简介:Inthisstudy,resistancespotweldabilityof180gradebakehardeningsteel(BH180),7123gradeinterstitialfreesteel(IF7123)and304gradeausteniticstainlesssteel(AISI304L)witheachotherwasinvestigated.Inthejoiningprocess,electrodepressureandweldcurrentwerekeptconstantandsixdifferentweldtimewerechosen.Microstructure,microhardness,tensile-shearpropertiesandfracturetypesofresistancespotweldedjointswereexamined.Inordertocharacterizethemetallurgicalstructureoftheweldedjoint,themicrostructuralprofilewasdeveloped,andtherelationshipbetweenmechanicalpropertiesandmicrostructurewasdetermined.Thechangeofweldtime,nuggetdiameter,theHAZ(heataffectedzone)widthandtheelectrodeimmersiondepthwerealsoinvestigated.WeldedjointswereexaminedbySEM(scanningelectronmicroscopy)imagesoffracturesurface.Asaresultoftheexperiment,itwasdeterminedthatwithincreasingweldtime,tensileshearloadbearingcapacity(TLBC)increasedwithweldtimeupto25cycleandtwotypesoftearingoccurred.ItwasalsodeterminedthatwhilethefailureoccurredfromIFsideattheBH180+IF7123joint,itoccurredfromtheBH180sideattheBH180+AISI304Ljoint.
简介:Non-metallicinclusionisthemainreasonforthepresenceofsurfacedefectsincold-rolledsteelstrip.Inthisstudy,thecomposition,morphology,andsizeofthenon-metallicinclusioninhot-rolled304stainlesssteelstripsareanalyzed.Cold-rolled304stainlesssteelstripswithdifferentcold-rollingreductionhavebeenprepared,andthemorphologyandsizeofinclusioninthesecold-rolledstripsarealsoanalyzed.Furthermore,thedeformationbehaviorofanon-metallicinclusionduringthecold-rollingprocessisstudied.TheresultsshowthatCaO-SiO2-MgO-Al2O3,akindofbrittlecompoundoxide,isthemaintypeofinclusioninhot-rolled304stainlesssteelstrips.Duringthecold-rollingprocess,ductiledeformationofthistypeofinclusionisnotobvious,wherelargeinclusionsarecrushed,andtheaveragesizeofinclusionsincold-rolledstripsdecreasedwhilethecold-rollingreductionincreased.
简介:GlowdischargeplasmanitridingofAISI304austeniticstainlesssteelhasbeencar-riedoutfordifferentprocessingtimeunderoptimumdischargeconditionsestablishedbyspectro-scopicanalysis.ThetreatedsampleswereanalysedbyX-raydiffraction(XRD)toexplorethechangesinducedinthecrystallographicstructure.TheXRDpatternconfirmedtheformationofanexpandedaustenitephase(γN)owingtoincorporationofnitrogenasaninterstitialsolidsolu-tionintheironlattice.AVickersmicrohardnesstesterwasusedtoevaluatethesurfacehardnessasafunctionofindentationdepth(μm).Theresultsshowedclearevidenceofsurfacechangeswithsubstantialincreaseinsurfacehardness.
简介:Objective:Toobservetheeffectsofthermalstressonproliferationofhumanvascularendothelialcells(VECs)andexploreitssignificance.Methods:ChangesofVECsproliferationwereinvestigatedwith3H-TdRincorporationmethodafterECV304wastreatedat43℃for2hours,whileexpressionsofintercellularadhesionmolecule-1(ICAM-1),inhibitorofdifferentiation-1(ID1),andP16andP21proteinsweredeterminedbyWesternBlotting.Results:TheeffectofinhibitionofVECsgrowthafterthermalstresswasdetectedby3H-TdRincorporationexperiment.WesternblottingshowedICAM-1,amarkerofactivatedendothelialcells,wasincreasedmarkedlyafterthermalstress.ExpressionofID1proteindeclinedgraduallywithincreasingexpressionsofitsdownstreamgenes,P16andP21followingthethermalstress.Conclusions:ThermalstresscouldstronglyactivateVECsandinhibitproliferationofVECsthroughID1,thusdownregulatingcyclin-dependentkinaseinhibitors,P16andP21,whichmightbeanessentialpathwayforrecoveryofVECsafterthermalstress.
简介:The304stainlesssteelstripsweredepositedonelayeroncarbonsteelbasemetalbyelectroslagstripcladding(ESC)andsubmergedarccladding(SAC),respectively.ThesolidificationmicrostructureofESCmetalwasanalyzedbytheopticalmicroscopy,scanningelectronmicroscopeandenergydispersivespectroscopy.Thecorrosionresistancestudiesofstripcladdingmetalswerecarriedoutin10%oxalicacidelectrolyticetchingtest.TheresultsshowedthatthecladdingmetalobtainedbyESCpresentedlowcontentofC,highcontentofCrandenoughalloyingelementofNiinthechemicalcomposition.ThetransitionzoneofESCwithsmallwidthwasalmostparallelwiththebasemetal,leadingtoalowerdilution.Therearethreetypesofsolidificationmodes(A→AF→FA)occurredintheESCmetalduetothedecreaseofcoolingrateanddegreeofdilutionfromthetransitionzonetothetopofESCmetal.Asaresult,themicrostructureofESCmetalexhibitedmainlyaustenitewithasmallamountofferrite,contributingtoachievementofbettercorrosionresistance.