6005A铝合金激光-MIG复合焊接与MIG焊接残余应力对比

Contrast of the residual stress of 6005A aluminum alloy welded by laser-MIG hybrid welding and MIG welding

试验采用激光-MIG复合焊接方法和MIG焊接方法焊接6 mm厚6005A铝合金,采用小孔法和X射线法测试接头残余应力,对激光-MIG复合焊接和MIG焊接的残余应力分布情况以及小孔法和X射线法对残余应力的测试效果进行对比分析。研究结果表明:激光-MIG复合焊接的焊接热过程对母材的影响明显小于MIG焊接,激光-MIG复合焊接的残余应力在整个接头范围内普遍低于MIG焊接,其高应力区明显窄于MIG焊接,与MIG焊接相比,激光-MIG复合焊接在控制接头残余应力方面具有显著优势;两种残余应力测试方法所测的残余应力分布曲线形状相似,重合度高,都很好的反映了焊接接头残余应力的分布规律,测试结果可靠,考虑到小孔法测试残余应力对车体存在一定的损伤,可以采用X射线法对焊接残余应力进行无损检测,对车体质量进行控制。

Laser-MIG hybrid welding and MIG welding were applied to weld 6 mm thick 6005A aluminum alloy,the residual stress of the welding joint was measured by hole-drilling and X-ray diffraction method,the distribution of the residual stress by both welding technology was comparative analyzed.The results showed that the effect of welding thermal process of laser-MIG hybrid welding on base metal was obviously less than that of MIG welding.The residual stress of laser-MIG hybrid welding was lower than that of MIG welding in complete joint range,and the high residual stress zone of laser-MIG hybrid welding was evidently narrower than that of MIG welding.Compared to MIG welding, laser-MIG hybrid welding has advantages on the control of the residual stress. The shape of residual stress curves measured by both testing methods was similar.Both of them can well reflect the distribution of residual stress, and the test results were reliable.Considering the damage to the vehicle body caused by hole-drilling method ,X-ray diffraction method can be chosen to non-destructive test residual stress and monitor the quality of the vehicle body.