Numerical and experimental investigation of vacuum-assisted laser welding for DP590 galvanized steel lap joint without prescribed gap

摘要

AbstractThe high-pressurized zinc vapor, which was developed at the interface of the two metal sheets due to the lower boiling point of zinc (around 906?°C) than the melting point of steel (over 1500?°C), led to the formation of macro-blowholes. Vacuum-assisted laser welding was a powerful approach to obtain a defect-free weld bead. The laser welding process was simulated to observe the dynamic or zinc vapor. The stability of laser welding was analyzed according to simulated results. The zinc distribution which was measured by EDS experiment also represented the influence of ambient pressure on welding stability. The bearing load for weld beads under different ambient pressure was measured by shear strength test. A defect-free continuous laser weld bead could be obtained under 3?kPa ambient pressure.]]>