镀锌钢板的激光焊接工艺与接头力学性能研究

Laser Welding Process and Mechanical Property of Welded Joint for Galvanized Steel Sheet

对DP780镀锌钢板进行激光对接焊接,研究了其焊接工艺参数变化对接头力学性能的影响。结果表明,激光功率越大或焊接速率越小时,热输入量越大,焊缝深度和宽度越大。焊缝和热影响区显微硬度高于母材,达到450-475HV。随着激光功率或焊接速率的增大,接头抗拉强度、屈服强度和伸长率先增大后减小。激光功率为1.4 kW、焊接速率为0.9 m/min时,抗拉强度为933.5 MPa,屈服强度为671.5 MPa,伸长率为13.1%。

DP780 galvanized steel was welded by laser butt welding, the welding process and mechanical properties werestudied. The results show that the larger the laser power is or the smaller the welding speed is, the greater the amount of heatinput is, the bigger the joint＇s weld depth and width are. The microhardness of the weld seam and heat affected zone is higherthan that of the matrix metal, which is 450-475 HV. With the increase of laser power and welding speed, the tensile strength,yield strength and extension of the welded joint increase firstly and then decreases. At the laser power of 1.4kW, the weldingspeed of 0.9 m/min, the tensile strength of the welded joint is 933.5 MPa, the yield strength of the welded joint is 671.5 MPaand the elongation is 13.1%.