中文摘要：

为了研究42CrMo钢中温成形性,本文通过Gleeble-1500D热模拟机开展了钢在不同温度下的等温热压缩试验。确定了合理的中温成形温度区间,并在该温度内研究了成形温度和应变速率对塑性变形行为和微观组织演化的影响。结果表明：42CrMo钢合理的中温成形温度为600~750℃;钢的真应力随成形温度的升高和应变速率的减小而降低,并且在高应变速率下,真应力-应变曲线呈现出明显的波动;在中温成形过程中,钢原始组织中的片状珠光体发生了明显的球化,铁素体和球状珠光体分布均匀性提高,并且随着成形温度的升高,球状珠光体聚集现象逐渐减少,得到的微观组织是球状珠光体均匀分布在42CrMo钢组织的铁素体基体上。

英文摘要：

In order to study the warm forming formability of 42CrMo steel, isothermal hot compression tests of the steel at different temperatures were carried out by Gleeble-1500D thermal simulation machine. The reasonable warm forming temperature region was determined, and the effects of forming temperatures and strain rates on the plastic deformation behavior and microstructure evolution were investigated within the reasonable warm forming temperature region. The results show that the reasonable warm forming temperature region of 42CrMo steel is 600-750 ~C ; the true stress of the steel decreases as the forming temperature increases and the strain rate decreases, and obvious fluctuation of the true stress-true strain curves appears under high strain rate; during the warm forming process, evident spheroidization of the lamellar pearlite in the origin microstructure of the steel occurs, the distribution uniformity of the ferrite and globular pearlite is improved, and the accumulation of the globular pearlite decreases as the warm forming temperature increases. The globular pearlite are uniformly distributed on the ferrite matrix in the microstructure of 42CrMo steel.