高锰TRIP/TWIP钢压缩过程晶体学行为的EBSD分析 Ⅱ.马氏体内取向差、取向变化及奥氏体取向的影响

来源期刊：金属学报2010年第6期

论文作者：杨平 鲁法云 孟利 崔凤娥

文章页码：666 - 673

关键词：高锰钢； EBSD； TRIP/TWIP； 马氏体相变； 取向差； 织构

Key words：high manganese steel； EBSD； TRIP/TWIP； martensitic transformation； misorientation； texture

摘    要：本文利用EBSD技术研究了高锰钢压缩变形过程中两类马氏体(六方结构ε-M和bcc结构α′-M)内的形变特征以及奥氏体取向对马氏体取向变化的影响.结果表明,马氏体形变过程中,ε-M内除继承相变取向关系外,主要是滑移造成的小角度取向差和特殊取向差93°〈7253〉.α′-M内除变体间产生的特殊取向差及奥氏体孪晶遗传下来的特殊取向差外,只有滑移产生的小角度取向差;ε-M内因滑移产生的取向差小于α′-M.压缩时{110}_γ取向晶粒发生γ→ε→α′相变较容易,{100}_γ取向晶粒内转变较慢,分别对应压缩时的稳定和不稳定取向;由于{110}_α′是不稳定的取向,又只能进行滑移,因此该取向的α′-M晶粒内取向转动较大.对六方结构马氏体内新出现的特殊取向差的成因及奥氏体取向的影响进行了讨论.

Abstract: In this paper,deformation behaviors of two kinds of martensites (hexagonal and bcc structures) and the influence of austenitic orientations on martensitic transformation in high manganese TRIP/TWIP (transformation-induced plasticity/twinning-induced plasticity) steels during compression were analyzed by EBSD technique.Results showed that,in hexagonal martensites low angle grain boundaries caused by slip and special misorientations such as 93°<7253> were detected in addition to those inherited due to orientation relationship.In bcc martensite,low angle misorientations due to slip were dominant in addition to the special misorientations between α’-M variants or those inherited from austenitic twins.Besides,austenitic orientations affected phase transformation and it was observed that martensite was induced faster in austenitic grains of {110}_γ orientation than that of {100}_γ orientation. α’-M orientation changed more obviously in {110}_α’ oriented grains because they were unstable during compression.The reasons for the formation of new special misorientations in hexagonal martensite and the influence of austenitic orientation were discussed.