20#钢连续驱动摩擦焊大变形及传热行为的有限元模拟研究

目的研究20~#钢连续驱动摩擦焊接过程工艺参数对焊接过程温度场和变形行为的变化规律。方法基于ABAQUS有限元软件二次开发环境,建立了20~#钢连续驱动摩擦焊接过程中的完全热-结构耦合模型。通过对比模拟和实验获得的焊接温度场、轴向缩短量和飞边形貌,对模型进行了验证。研究了工艺参数对摩擦焊接过程温度场与大变形行为和接头组织与性能的影响规律。结果在不稳定摩擦阶段,峰值温度出现在外表面附近。在稳定摩擦阶段,峰值温度稳定在距焊缝中心约2/3半径位置。接头温度的升高速度随着摩擦压力和转速的增大而增大,摩擦压力和转速对稳定阶段温度场的影响很有限;经过顶锻阶段之后摩擦面温度分布更加均匀,顶锻力越大在接头相同的位置温度越低,顶锻力越大轴向缩短量越大。结论所建立的完全热-结构耦合模型可以模拟20~#钢连续驱动摩擦焊接过程的塑性变形过程,在不稳定摩擦阶段,摩擦压力和转速对温度场和变形的影响较大。在稳定摩擦阶段,摩擦压力和转速对温度场的影响不显著。顶锻阶段轴向缩短量随着摩擦压力、转速和顶锻压力的增大而增加。

Finite Element Simulation of Large Deformation and Heat Transfer in Continuous Drive Friction Welding of Steel 20#

The paper aims to study the change law of 20# steel continuous drive friction welding process parameters on the temperature field and deformation behavior of the welding process. Based on the secondary development environment of the ABAQUS finite element software, a complete thermo-structure coupling model for continuous drive friction welding of 20# steel was established. The model was verified by comparing the welding temperature field, axial shortening, and burr morphology obtained from simulation and experiment. The effects of process parameters on the temperature field and large deformation behavior and the microstructure and properties of joints during friction welding were studied. The results show that the peak temperature appeared near the outer surface during the unstable friction stage. In the stable friction phase, the peak temperature was stable at a radius of about 2/3 from the center of the weld. The temperature rise of joint increased with the increase of friction pressure and rotation speed. The influence of friction pressure and rotation speed on the temperature field in the stabilization phase was limited; after the upset phase, the temperature distribution on the friction surface was more uniform. The larger the upset force, the lower the temperature at the same location of the joint; the greater the upset force and the greater the axial shortening. The established complete thermal-structure coupling model can simulate the plastic deformation process of the 20# steel continuously driven friction welding process. In the unstable friction stage, the friction pressure and speed have a greater impact on the temperature field and deformation. In the stable friction stage, the influence of friction pressure and speed on the temperature field is not significant. The amount of axial shortening in upset stage increases with the increase of friction pressure, speed and upset pressure.