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.
Transactions of Nonferrous Metals Society of China
Projects(31665004,31715011)supported by the Open Fund of State Key Laboratory of Advanced Design and Manufacture for Vehicle Body,Hunan University,China
Project(15C0450)supported by the Educational Commission of Hunan Province of China.
double-pulse MIG welding
welding residual stress
Corresponding author:Jie YI;Tel:+86-15111270111;E-mail:email@example.com.