高锰钢切变型动态相变过程的EBSD分析

Shear type dynamic transformation in high manganese steels analyzed by EBSD technique

形变作用下的切变型相变(如TRIP过程)具有显著的取向依赖性、变体选择规律及织构效应。高锰钢中存在热致马氏体和应变诱导马氏体及γ→ε→α'顺序产生两种马氏体过程,使组织演变过程十分复杂。EBSD取向成像技术可十分便捷地定量揭示相变过程信息,为认识切变型动态相变提供重要数据。本文总结了利用EBSD技术揭示高锰钢单向拉伸、压缩时马氏体相变的取向关系识别、取向依赖性、变体选择规律、织构效应和奥氏体状态的影响及逆相变特点,表明EBSD技术研究马氏体相变的优势。EBSD数据分析认为,取向依赖性、变体选择规律及织构效应是动态转变的共性规律。

Strain induced shear-type transformation demonstrates strong orientation dependence,variant selection and texture effects.In high manganese steels the related effects and microstructure evolution are further complicated by two types of martensite,namely thermally-induced and strain-induced,as well as the transformation sequence of γ→ε→d.EBSD orientation mapping can quickly reveal and collect massive structural and orientational quantitative information and therefore provides us important data for understanding the underlying mechanisms.This work summarizes the identification of orientation relationship of martensitic transformation,orientation dependence,variant selection,texture effects,the influence of austenite state and reverse transformation in tensile/compressed high manganese steels using EBSD technique.