42CrMo铸坯环件热辗扩有限元模拟与分析

Finite element simulation and analysis of hot ring rolling process for 42CrMo as-cast ring

基于ABAQUS软件平台,建立了42CrMo大型环形铸坯热辗扩三维热力耦合有限元模型,模拟了铸坯热辗扩过程中应变场和温度场,研究了初始辗扩温度对辗扩力的影响规律。模拟结果表明在环形铸坯热辗扩过程中:1铸坯等效应变呈阶梯状上升,内外表面应变大于中间层应变;在稳定成形阶段,沿环件径向方向,由于导向辊与芯辊直径差异,导致环件最大平均等效应变可能出现在环件内表面也可能出现在环件外表面;2初始阶段,变形区与成形辊接触处温度降低较快,非变形区温度变化不是很明显;随着辗扩的进行,芯部温度逐渐上升,边缘温度低,温度分布不均匀;3随着铸坯初始辗扩温度升高,平均辗扩力明显下降,但随时间变化趋势保持一致。

On the basis of ABAQUS software platform, the 3D thermal coupled finite element model of hot rolling process for 42CrMo large as-east ring has been established. The distribution of strain field and temperature field of hot rolling process for as-cast ring has been simulated. Moreover, the influence law of initial rolling temperature to rolling force has been studied. The results during ring rolling process have been shown as follows： ①the equivalent strain increases as a stepped slab, and the strain on inner part and outer surfaces is larger than intermediate layer. However, during the period of the stable forming, as the different diameter of the guide and core roll, the maximum average equivalent strain maybe appears in the inner or outer surface of ring;②the temperature change of non-deformable zone in the initial deformation stage is slight but the temperature of contact area between deformable zone and the forming rolls reduces rapidly;as the rolling continues, the core temperature gradually increases and the edge temperature is still low,while the temperature distribution is not uniform; ③with the increase of initial rolling temperature, the average rolling force is dramatically declined at first and then turns to be consistent after a period time.