采用静态拉伸、金相组织观察方法研究了5种不同锰含量的TWIP钢的拉伸应变硬化行为。结果表明：5种钢的真应力与真应变不遵循Hollomond的线性关系，其中1号钢的应变硬化指数n值随真应变的增大先升后降，其它4种成分钢的n值随真应变的增大而提高。对于同一成分的钢，其n值均随应变速率的增大而减小。其微观变形机制是：随着锰含量的增加，孪晶形成逐渐起主导作用；拉伸前组织中有退火孪晶；随着变形的进行，产生大量的形变孪晶，孪晶与位错之间的交互作用与硬化率相协调，从而延迟了颈缩的产生，导致TWIP钢具有很高的均匀变形能力。
The strain hardening behaviour of five TWIP steels with different Mn content was investigated by static tensile test and metallography. The results show that Hollomond relationship is inapplicable. The n value of No.1 steel was increased first and then decreased with increasing true strain. However, the n value of other steels was increased with increasing true strain. Moreover, for the same steel, the n value was increased with increasing strain rate. The micro mechanisms are:with the increase of Mn content, formation of the twin will gradually play a leading role. There are many annealing twins before tension. With the development of deformation, many deformation twins are formed. The interaction between twins and dislocations are coordinated with strain hardening rate. Subsequently, the necking is delayed and the ability of uniform deformation is obtained.
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