Effect of work hardening on mechanical behavior of resistance spot welding joint during tension shear test

摘要

Thickness variation and plastic strain caused by forming process will severely affect the crash behaviors. The objective of this paper was to investigate the effect of work hardening on mechanical behavior in resistance spot welding. The microstructure and mechanical properties of as-received DP780 steel sheet (0%) and tensile stretched DP780 with 4%, 8% and 12% of pre-strain degree were scanned and analyzed as baselines, which were then jointed with press quenched 22MnB5 hot-stamping steel using resistance spot welding. The influence of work hardening on mechanical behavior, hardness profile and heating effected zone softening of welded joints were explored separately. It was concluded that the work hardening could promote load bearing capacity of spot weld joints by about 5% and induce a significant 20% drop down in energy absorption capability. (C) 2016 Elsevier Ltd. All rights reserved.