简介：ＭｏｄｉｆｙｉｎｇＥｆｅｃｔｏｆＲａｒｅＥａｒｔｈｓａｎｄＴｉｔａｎｉｕｍｏｎＡｕｓｔｅｎｉｔｉｃＭａｎｇａｎｅｓｅＳｔｅｌＺｈｕＲｕｉｆｕ（朱瑞富），ＬüＹｕｐｅｎｇ（吕宇鹏），ＬｉＳｈｉｔｏｎｇ（李士同）ＣｈａｏＺｈｉｑｉａｎｇ（朝志强），Ｗａ...

简介：OnthebasisofquantitativeevaluationofsusceptibilitytosolidificationcrackingwithTrans-Varestraint-Test,themicrostructuresoftwostainlesssteelsof316Landalloy800HwithdifferentCreq/Nieqratiosduringsolidificationprocesswereanalyzedwithseveralmethods.Itisconcludedthatthesusceptibilitytosolidificationcrackingof316L-stainlesssteelismuchlowerthanthatofalloy800Hduetodifferentsolidificationbehaviorsoftheweldmetalofthetwomaterials.Theweldmetalofalloy800Hsolidifiesintheformofprimaryaustenitewhoseboundariesarestraightandsmoothandeasilywettedbylowmelting-pointliquidphases,whichincreasesthesusceptibilitytosolidificationcracking;whilethe316Lweldmetalsolidifiesintoprimaryaustenite/ferrite.Owingtoaseriesofdynamicmicrostructurechangesduringsolidificationsuchasperitecticreactions,migrationofausteniticboundariesandnailingofδ-ferritetotheboundaries,thegrainsbecomefiner,theorientationsofcolumnargrainsgetdisorderedandtheboundariesarecurvedandcomplex.Alsohightemperatureδ-ferriteexists,segregationofimpuritiesatboundariesdecreasesandtheboundariesarehardtobewettedbyliquidfilms,whichreducesthecrackingsusceptibility.

简介：Theeffectofcathodichydrogenchargingonthetensileandconstantloadpropertieswasdeterminedforanausteniticstainlesssteelweldmentcomprisinga304Lsteelinthesolutiontreatedconditionasabasemetalanda308Lfillersteelasaweldmetal.Partofthe304Lsolutiontreatedsteelwasseparatelygivenadditionalsensitizationtreatmenttosimulatethemicrostructurethatwoulddevelopintheheataffectedzone.Testswereperformedatroomtemperatureonnotchedroundbarspecimens.Hydrogenchargingresultedinapronouncedembrittlementofthetestedmaterials.Thiswasmanifestedmainlyasaconsiderablelossinthedluctilityoftensilespecimensandadecreaseinthetimetofailureandthresholdstressofconstantloadspecimens.The308Lweldmetalexhibitedthehighest,andthe304Lsolutiontreatedsteelthelowest,resistancetohydrogenembrittlement.Hydrogenembrittlementwasassociatedwiththeformationofstraininducedmartensiteaswellasatransitionfrombrittletoductilefracturemorphologyonwardsthecentreofthespecimens.

简介：Theeffectofnonmetallicinclusionsinthedropletofthestainlesssteelcoveredelectrodeontheporositywasresearched.Theresultshowsthatthenonmetallicinclusionsinthedropletarespherical,theircompositionisdifferentfromtheoneofslagandtheinclusionshavethecharacterof"innerformation".Whentheratioofrutiletoilmeniteinthecoatedmaterialisincreased,thedropletbecomescoarse,thecontentofnonmetallicinclusioninthedropletdecreases,andtheporositysensitivityintheweldmetalalsodecreases.Whentheratiooffledspartoilmeniteinthecoatedmaterialisincreased,thedropletbecomesfine,thecontentofnonmetallicinclusioninthedropletincreases,andtheporositysensitivityintheweldmetalincreases.WhentheratioofFe2O3toilmeniteinthecoatedmaterialisincreased,thedropletbecomesfine,thecontentofnonmetallicinclusiondecreases,whiletheporositysensitivitydoesnotreduce.