简介：FSWandTIGwereconductedon316Lstainlesssteel.Variationduringmicrostructureandpropertiesinjointsobtainedbydifferentweldingmethodswasstudied.TheresultsshowthattheeffectofseveremechanicalstirringandintenseplasticdeformationcreatafinerecrystallizedgrainintheweldingjointduringFSW.AsforTIG,thetemperatureofweldingjointexceedsthemeltingpointofweldedmaterialitself.Theentireweldingprocessbelongstothesolidificationofasmallmoltenpool;andthemicrostructureofthejointtakesonatypicalcastingstructure.Whentheweldingparameterswereselectedappropriately,theaverageultimatetensilestrengthofFSWjointscanreach493MPa,whichis83.6%ofbasemetal;theaverageelongationis52.1%ofbasemetal.TheaverageultimatetensilestrengthofTIGjointsis475MPa,whichis80.5%ofbasemetal;theaverageelongationis40.8%ofbasemetal.ThetensiletestofFSWjointsissuperiortotheTIGjoints.ThemicrohardnessofFSWjointcomparedtobasemetalandTIGjointhavingasignificantimprovement,whicharel95.5HV,159.7HVand160.7HV,respectively;grainrefinementstrengtheningplaysanimportantroleinenhancingthemicrohardness.TheelectrochemicalcorrosiontestsshowthatthejointofFSW316Lausteniticstainlesssteelhasagoodcorrosionresistance.

简介：Improvingtheunitheatefficiency,reducingcoalconsumptionandtheemissionofCO2andmeetingtherequirementsofenvironmentalprotectionandenergyconservationisthegoaloftheboilerandthepowerindustry.Developmentsoflargecapacityandhighparameterultra-supercritical（USC）unitsarethetendencyofthepowerindustry.ThereisnodoubtthatthedevelopmentofUSCunitsisbasedonthedevelopmentofmaterials,especiallythematerialsusedforsuper-heaterandreheaterinhigh-temperatureUSCboiler.Duetothelongtimeexposuretotheharshenvironment,suchasbearingthe600℃steamoxidation,andwithstandingthecorrosivefluegasandflyasherosion,thematerialsrequirenotonlygoodhigh-temperaturestrength,butalsoagoodcorrosionresistance.Inconsiderationoftherequirementscitedabove,foreigncountrieshaddevelopedTP310HCbN（07Cr25Ni21CbN）austeniticheat-resistantsteel.However,thedomesticdemandsforthismaterialstilldependonimportandthecostishigh,sotheboilerandthepowerindustryexpectseagerlythatthesesteelscanbeproducedbydomesticmetallurgicalindustry,especiallyBaosteel,toreplacetheimportedproducts.Inordertosatisfytherequirementsofdomesticmanufacturingsuper-heaterandreheaterusedinultra-supercriticalpowerboiler,afterdevelopedT23、T91、T92、S30432highpressureboilertube,BaosteelbegantodevelopTP310HCbN（07Cr25Ni21CbN）austeniticstainlesssteeltubeinJanuaryof2007.Thisstudydescribesthecompositiondesign,themanufacturingprocessofproduct,andtheassessmentofperformanceofBaosteel’sTP310HCbN（07Cr25Ni21CbN）.ThedataindicatesthatpropertiesofBaosteel’sTP310HCbN（07Cr25Ni21CbN）conformtotheASMESA-213standardandGB5310standard,soitcansubstitutetheimportedproductsandissuitableformanufacturingpowerstationboilerofgreatcapacityandhighsteamparameters.