材料期刊网

对不同形变量下TWIP钢内部组织连续观察发现：在形变量为5%时，晶粒内出现大量的位错，无孪生现象发生；在形变量为10%时，金相下可以观察到片条状类似孪晶组织出现，TEM观察发现晶粒内部位错密度很高；在更大变形量下，形变孪晶大量产生，出现不同孪生系统的相互交割以及二次孪生现象，晶粒被孪晶分割成胞状组织。大变形下，组织中出现少量的剪切碎化带。 对比分析各形变量下组织情况可以发现TWIP效应过程主要有如下几点：（a）孪晶对位错的阻塞作用，提高了局部加工硬化能力，使应变向其他较低区域转移；（b）孪晶与孪晶的作用：孪晶的形成增加了后续孪晶的阻力，其次多套孪生系统有效的对晶粒进行了分割，增加了孪晶界面，从而提高了加工硬化能力；（c）孪生过程本身具有一定的型变量。

With continue observing the microstructural of TWIP steel at different tension, we find that: lots of dislocation can been seen in crystal grains and twin can’t be found at ε=5%; when the tension is up to 10%, lots of flakes like twins can be seen in crystal grain by optical microscope, and more higher density can be seen by transmission electronic microscope; in the larger tension, lots of deformation twins were produced, and more twinning systems were activated and twin bands intersected each other. Crystal grain is cut to cell by twins. The TWIP effect were found during tension: (a) dislocation were against by twins, work handing were raised in this part so made the tension in other parts. (b) The twins which were produced in the fist were against the twins which were produced as follow, and the more twin boundaries also against dislocation to move, so work handing continue raised. (c) The process of twins have a lot of deformation.