中文摘要：

研究合金成分为18 M n-0 .15C-3Si-3 Al的高锰T RIP/T W IP钢（18 M n钢）在 40 ～200oС 范围内的拉伸变形行为,分析形变温度对其拉伸性能、相组成和显微组织的影响. 采用EBSD取向成像分析方法着重研究了〈111〉取向的奥氏体晶粒在拉伸过程中的相组成变化. 结果表明,随着形变温度的升高,18 M n钢的抗拉强度和延伸率大体上呈降低趋势,T RIP效应很快消失,形变孪晶和位错滑移取代马氏体相变成为主要的形变机制,即奥氏体晶粒内形变机制的变化为：α’- M相变→ε- M相变→形变孪晶→位错滑移.18 M n钢中较硬的铁素体在形变过程中能提高材料的加工硬化率,但同时也会引起低温脆性

英文摘要：

The tensile deformation behavior of 18Mn-0.15C-3Si-3Al steel was investigated at temperatures ranging from --40℃to 200 ℃. The influence of deformation temperature on tensile properties, phase constitutes and microstructure of the steel was analyzed. EBSD measurement was used to reveal the change of phase constitutes in （111）-oriented austenitic grains. The results show that, as the temperature rises, both tensile strength and elongation decrease and TRIP effect disappears fast, and me- chanical twinning and dislocation slip dominate. The deformation mechanism evolution is that a＇-martensitic transformation →ε-martensitic transformation →mechanical twinning →dislocation slip. Besides, the harder ferrite in 18Mn steel can enhance work hardening rate, yet causing low temperature brittleness.