中文摘要：

对锰含量为18．8％的TRIP／TWIP钢进行单轴拉伸实验，研究了这种钢的应变硬化行为．结果表明：这种高锰TRIP／TWIP钢的真应力应变曲线不完全遵循Hollomon的线性关系，在不同变形阶段强化机制不同．在塑性变形的开始阶段TRIP效应比较明显，且应变硬化指数n是恒定的；而真应变在0．14—0．35之间时二阶导数d^2σ／dε^2〉0，应变硬化指数n随着应变量的增加而增加，其微观机制是形成大量的形变孪晶，并有孪晶和位错的交互作用，TWIP效应在该阶段占主导作用．真应变大于0．35后有少量TRIP效应，此时两相均发生变形．

英文摘要：

The tensile tests were carried out to study the strain hardening behavior of a high manganese TRIP/TWIP steels with 18.8% manganese. The results indicated that, strain hardening behaviors are different during the deformation process. True stress-strain curve obeys Hollomon relationship partly. TRIP effect occurs in the initial plastic stage, and the strain hardening exponent in this stage is a constant. However, the value of n increases with true strain ε increasing, when true strain is between 0.14 and 0.35. Then the value of d^2σ/dε^2 is above zero. A lot of deformation twinning can be found, and the micro mechanisms are ＂twins induced plasticity＂ . TWIP effect dominates this stage. The mechanism of the last stage is some TRIP effect, and both phases have occurred plastic deformation.