中文摘要：

利用Gleeble 3500热力模拟试验机对45、T8和T12钢淬火马氏体（M）组织进行单轴温压缩实验,变形温度为550～700℃,应变速率为1.0～0.001 s-1,测定3种钢M组织的应力-应变曲线,对比研究碳含量、变形温度和应变速率对其流变行为的影响。测试结果表明,同一应变速率随着变形温度的升高以及同一变形温度随着应变速率的降低,其M组织的流变应力都随之降低;由于材料的自扩散激活能随着碳含量的增加而减小,碳含量越高其回复再结晶速度越快,流变应力越低,使得中碳钢M组织的流变应力高于高碳钢,其中流变应力高低排列为：45钢〉T8钢〉T12钢。

英文摘要：

For the quenched martensite （M） structure of steel 45, T8 and T12, the uniaxial warm compression tests were investigated by a Gleeble 3500 machine within the temperature between 550 ℃ and 700 ℃and the strain rate from 1.0 s-1 to 0. 001 s-1. The stress- strain curves of M structure in above three steels were measured. The influences of carbon content, deformation temperature and strain rate on flow behavior were studied comparatively. The test results show that the flow stress of M structure decreases with increasing of deforma- tion temperature or decreasing of strain rate. Because the activation energy of self-diffusion decreases with increasing carbon content, the more the carbon content, the faster the rate of recovery and recrystallizations and the lower flow stress, which makes flow stress of medium carbon steel M structure higher than that of high carbon steel, and the sequence of flow stress in steels is that 45 steel is the highest, T12 steel is the lowest and T8 steel is among them.