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1、材料科学基础第一章材料的结构前言材料热处理学报，29（1），99－101，2008304奥氏体不锈钢热诱发马氏体相变研究杨卓越、王 建、陈嘉砚摘 要:借助X射线衍射技术,研究了304奥氏体不锈钢热诱发马氏体相变倾向。结果表明:C、Mn、Cr和Ni接近标准规范下限,304不锈钢的稳定性急剧下降,致使液氮内冷却后的奥氏体转变为α′或ε马氏体,室温拉伸即形成应变诱发ε和α′马氏体,而且较小的室温变形显著增大随后液氮内冷却的热诱发α′马氏体相变倾向,但随室温预应变增大快速形成应变诱发α′马氏体,致使随后在液氮内发生热诱发α′马氏体倾向下降。此外,研究表明ε马氏体的形成及消失与α′马氏体
2、的累积量有关。ShuiLi,JinTao,TianSugui,HuZhuangqi:Influenceofprecipitatemorphologyontensilecreepofasinglecrystalnickel-basesuperalloyAbstractTheinfluenceoftheprecipitatemorphologyonthecreeppropertiesof[001]-orientatedspecimensofanickel-basesinglecrystalsuperalloyhasbeeninvestigated.Specimenswithtwod
3、ifferentmicrostructures,namelyas-heattreatedcrystalswithcuboidalparticlesandcrystalsgivenacompressionpre-treatmenttoformaraftmicrostructureorientatedparalleltothestressaxis,werecreptat800and1000◦C.Theanalysisoftheexperimentsshowthat,at800◦Cand600MPa,thealloywithcuboidalprecipitatesexhibitedb
4、othlowercreepratesandlongerrupturelivescomparedtothosewithrafted.TEMexaminationshowedthat,inadditionto{111}110-slipsystemoperatedinmatrix,theprecipitatesarecutbysuperlatticedislocationsandstackingfault.Itindicatedthatdislocationscouldshearthesemi-coherentraftsrelativelyeasilyomparedtothecohe
5、rentcuboidal.At1000◦Cand200MPa,thealloywithraftmicrostructureexhibitedanextremelylowminimumcreeprateandlongerrupturelife.Thedislocationsmovementbythecombinationofclimbingandglidingprocessesandtheglide–climbalong/verticalinterfacesareimpededmoststrongly.Thisindicatesthattheraftedstructureisbe
6、neficialtoimprovingcreepresistanceofthealloyunderthetestcondition.MaterialsScienceandEngineeringA454–455(2007)461–466Fig.5.Dislocationstructureofaprecompressiontreatmentspecimensduringcreepat800◦Cand600MPa:(a)t=0,(b)t=10h,(c)t=50hand(d)afterfailatt=287h.Fig.8.Schematicofdislocationshearingpr
7、ecipitatebystackingfault相关概念：304不锈钢热诱发:液氮－拉伸变形－液氮－X光、TEMγ奥氏体α´立方马氏体ε六方马氏体X射线、TEM：111200220311nickel-basesuperalloy[001]-orientated:[001]位向singlecrystal：单晶体cuboidalparticles：立方系颗粒{111}110-slipsystem：滑移系dislocationsandstackingfault：位错和层错dislocationsc
