为了解决高强度钢方管难变形、易开裂等成形难题,在传统冷成形工艺基础上,引入局部感应加热技术.基于矢量磁位法和物理环境法,利用ANSYS参数化设计语言建立局部感应加热电磁-温度场耦合模型.在不同加热工艺参数下进行数值模拟,并采用优化后参数进行实验研究.模拟结果表明,导磁体通过增大磁场强度,可以明显提升感应加热效率.加热频率越高,外圆角区域加热速度越快,但与内圆角区域之间的温差也越大.加热功率越高,高温区域和温度峰值越大,但外圆角区域更容易过热.实验结果表明,采用优化后的加热工艺参数,可以获得圆角半径极小、角部厚度增加且没有裂纹缺陷的高强度钢尖角方管.加热温度模拟值与实测值的误差均值约为7.57%,说明有限元模型具备良好预测精度.

In order to solve the forming problems such as difficult deformation and easy cracking of high strength steel square tubes, the local induction heating technology has been introduced based on the traditional cold forming process. An electromagnetic-temperature multi-field coupling model for local induction heating is established by using ANSYS parametric design language based on the magnetic vector potential and physical environment method. A numerical simulation is conducted at different heating process parameters, and the optimized parameters are used for experimental research. The simulation results show that the induction heating efficiency can be significantly improved by using magnetizers to increase the magnetic field intensity. As the heating frequency increase, the heating speed of the outer fillet area and the temperature difference between the outer and inner fillet area increase. As the heating power increases, the high temperature area and the peak temperature increase, but the outer fillet area is more prone to be overheated. The experimental results show that a high strength steel square tube with an extremely small fillet radius, increased corner thickness, but with no crack defect can be obtained by using the optimized heating process parameters. The average error between the simulated and measured heating temperature is about 7.57%, indicating that the finite element model has a good prediction accuracy.