焊接顺序对6061-T6铝合金汽车结构件焊接残余应力及变形的影响（英文）

Effect of welding sequence on residual stress and deformation of 6061-T6 aluminium alloy automobile component

采用ABAQUS软件中的非线性弹塑性有限元方法,对6061-T6铝合金汽车保险杠进行4种不同的双脉冲MIG焊接顺序试验。在4种焊接顺序下焊接后的残余应力和变形均有明显差异。结果表明,在方案A中,最高温度高于基体金属的熔点约200°C。这种大的温度梯度导致较高残余应力,且残余应力主要集中在横梁与吸能盒的焊缝附近。焊接变形主要是由于横梁两端的收缩和吸能盒的自收缩。与其他焊接顺序相比,方案A中残余应力最小,焊接变形最大。然而,由于方案B有效地降低了残余应力和满足良好的装配要求,因此,方案B是本研究得到的最优焊接方案。

Four different welding sequences of double-pulse MIG welding were conducted for 6061-T6 aluminum alloy automobile bumpers by using nonlinear elastoplasticity finite element method based on ABAQUS software.The post-welding residual stress and deformation were definitely different among the four welding sequences.The results showed that the highest temperature in Solution A was approximately 200℃higher than the melting point of base metal.High residual stress was resulted from this large temperature gradient and mainly concentrated on the welding vicinity between beam and crash box.The welding deformation primarily occurred in both of the contraction of two-ends of the beam and the self-contraction of crash box.Compared with other welding sequences,the residual stress in Solution A was the smallest,whereas the welding deformation was the largest.However,the optimal sequence was Solution B because of the effective reduction of residual stress and good assembly requirements.