Evaluation of morphology and mechanical properties of austenitic stainless steel 316L exposed to high-velocity liquid PbBi at high temperature

(整期优先)网络出版时间:2016-04-14
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Intheacceleratordrivensub-criticalsystem(ADS)cooledbyliquidPbBialloy,theausteniticstainlesssteel316Lisoneofthecandidatesofstructuralmaterials.However,thecorrosionandwearbehaviorof316Lsteelinthehigh-velocitystreamofliquidPbBiisthemostessentialissue,whichisurgenttobepaidcloseattention.Inordertoacquirethemorphologyandmechanicalpropertiesof316Lsteelintheconditionsofdifferentrelativeflowingvelocity(RFV),respectively2.62m/s,3.69m/s,4.77m/s,theexperimentwascarriedoutindynamicliquidPbBiat550℃,uptoabout1500h.Accordingtotheresults,thesurfaceof316LhasbeencorrodedbadlyandtheelementsofNi,Cr,etc.werefoundtodissolvealot.WiththeincreaseoftheRFV,thefeatureof316Lsurfacechangedfromthesurfacewithmuchdeeperpitsandlooserstructurestotherelativeplanarone,andthethicknessoftheouteroxidelayerdecreasedgraduallywhilethatoftheinneroxidelayerdiminishedalittle,andthemicrohardnessoftheoutermostsubstratealsodeclinedincreasingly,inaddition,thedomainofthepartialsubstratewithitsmicrohardnessbeingaltereddeepenedfurther.Theseexperimentaldatawouldoffertheoreticalbasisandpracticalvaluestostudycorrosionconditionof316LsteelinliquidPbBiwithhigh-velocity.