电磁脉冲磁场降低Q690钢焊接残余应力的研究

Research on Reduction of Welding Residual Stress of Q690 Steel Based on Electromagnetic Pulse Magnetic Field

针对Q690高强钢焊接存在较高残余应力的问题,采用电磁脉冲磁场改变材料内部结构的方法以降低焊接残余应力。研究结果表明:磁场处理最佳参数为频率10 Hz,峰值电流25 A,处理时间30 s,磁场强度1.3 T,占空比20%,横向残余应力平均降低率为41.6%,纵向残余应力平均降低率为54.3%。随着磁场强度的增加,残余应力降低率增大,磁头与测量点的距离为5 mm时残余应力降低效果更强。一定值的磁场强度促进材料内部原子迁移,原子达到一个更稳定的低能态,从而降低了残余应力。研究结果可为开展降低或消除残余应力提供一种思路和数据参考。

Aiming at the problem that high residual exists in the welding of Q690 high strength steel, in order to reduce the residual stress of Q690 high strength steel welding, electromagnetic pulse magnetic field was used to change the internal structure of the material. The results show that the best parameters for magnetic field processing are that the frequency is 10 Hz, peak current is 25 A, processing time is 30 s, magnetic field strength is 1.3 T, duty ratio is 20%, the average reduction rate of transverse residual stress is 41.6 %, and the average reduction rate of longitudinal residual stress is 54.3%. As the magnetic field intensity increases, the residual stress reduction rate increases, and the residual stress decreases more strongly when the distance between the head and the measurement point is 5 mm. A certain value of magnetic field intensity promotes the internal atomic migration of the material, and the atom reaches a more stable low energy state, and then reducing the residual stress. It can provide a idea and data reference for reducing or eliminating residual stress.