不同振动加速度下MAG焊缝显微组织及残余应力分析

Microstructure and Residual Stress Analysis of MAG Weld under Different Acceleration

为了进一步优化Q450NQR1高强钢的焊接质量,在Q450NQR1的MAG(熔化极活性气体保护电弧焊)过程中施加机械振动,研究振动加速度对焊缝显微组织及焊缝残余应力的影响。根据试验结果,在焊接过程中施加机械振动,可以促进焊缝中针状铁素体的形成,随着振动加速度的增加,焊缝中针状铁素体含量增加;机械振动可降低焊缝中的纵向残余应力,当振动加速度为9.85 m/s2时,焊缝纵向残余应力下降幅度最大。与传统MAG焊相比,最大残余应力下降幅度为11.73%,最小残余应力下降幅度为10.03%。研究结果表明,振动对Q450NQR1的残余应力有显著的抑制作用。

In order to further optimize the welding quality of Q450NQR1 high-strength steel,mechanical vibration is applied in the MAG process of Q450NQR1,and the effect of vibration acceleration on weld microstructure and residual stress is studied.According to the test results,the application of mechanical vibration during welding can promote the formation of acicular ferrite in the weld,and the content of acicular ferrite in the weld increases with the increase of vibration acceleration.Mechanical vibration can reduce the longitudinal residual stress in the weld.When the vibration acceleration is 9.85 m/s2,the longitudinal residual stress in the weld decreases the most.Compared with the traditional MAG,the maximum residual stress decreases by 11.73%and the minimum residual stress decreases by 10.03%.The results show that vibration has a significant inhibitory effect on the residual stress of Q450NQR1.