对Fe－22Mn－3Si－2Al高锰TRIP/TWIP钢拉伸变形后的组织、性能特点进行研究, 利用EBSD技术分析了形变过程中马氏体相变的晶体学特点. 结果表明, Fe－22Mn钢形变前含有大量硬度高于奥氏体的热致ε－M; 拉伸变形后, 热致ε－M转变为α’－M, ε－M与α’－M相变有明显的先后顺序, 即具有不同步性. Fe－22Mn钢拉伸时TRIP效应和TWIP效应共存, 具有良好的塑性和强度结合, 且ε－M没有引起低温脆性.热致ε－M为倾转的基面取向, 形变时易发生基面滑移, 并发生少量86°<11200>孪晶, 在出现30°<0001>误标后与ε－M基体形成93°<7253>取向关系. 形变后α’－M取向绕<110>转动, 变得漫散, 形成“彗星拖尾”现象. 同时, 形变过程中奥氏体的取向也发生转动, 产生绕<110>轴的小角度取向差. 此外, 原始奥氏体中的大量退火孪晶界对马氏体相变有促进作用.

High manganese steels demonstrate significant potential for industrial application due to their remarkable TRIP/TWIP effects at room temperature. Thus, they attract interest of many researchers. In this work, mechanical properties and microstructure evolutions of an Fe－22Mn－3Si－2Al TRIP/TWIP steel after tensile deformation were studied by mechanical tests and SEM analysis, and in particular, the crystallography of martensitic transformation was analyzed by EBSD technique. The results show that, plenty of harder thermalε－martensite existed before deformation and transformed to α’ －martensite during tensile deformation, namely the two kinds of martensite transformed asynchronously. During deformation, the TRIP effect by strain induced α’－martensite and the TWIP effect by deformation twinning coexisted, leading to good combination of strength and ductility in this steel, and furthermore, ε－martensite didn't cause the low temperature brittleness. The thermal ε－martensite showed tilting basal texture. When deformed,basal slip was an easy activity, whereas deformation twinning of 86°<1120> was also detected, which sometimes revealed 93°<7253> relationships by a combination of 30°<0001> misorientation due to mis－indexing of pseudosymmetry during EBSD measurement. During tensile deformation α’－martensite revealed a rotation around crystallographic <110> axis and scattered orientations, forming the phenomenon of comets trailing. Besides, austenitic orientations also rotated and increased low angle misorientations. And annealing twins in austenite was found to facilitate the martensitic transformation.