工艺参数对镀铝锌钢板点焊接头质量与组织的研究

摘要

By the spot welding experiments of Al-Zn alloy coated steel,the metallographic analysis and the shear experiment have been earned out to the spot welding joints achieved by twelve group processing parameters.The result indicates that the joint is lack of fusion in lower welding current or shorter welding time;and too higher current can cause more splashing in welding,the overproof depth of indentation on spot weld,and the stronger directional rough columnar crystals;and enhancing welding force properly can make the columnar crystals leaning or directional weakly.It is defined that the more appropriate processing parameters for 0.8 mm Al-Zn alloy coated steel spot welding is I=8.5?9.0 kA ,T= 14 cyc,FW =2 400 N,by the group processing parameter in welding,both the spot-welded joint's resisting shear and the nugget size are above A-level requirement in the standard of "Method of Inspection for Spot Weld",and the penetration rate and the depth of indentation on spot weld meet the quality requirements.%通过镀铝锌钢板点焊实验,对十二组不同工艺参数下获得的点焊接头进行抗剪力实验和金相分析,研究表明:当采用较小的焊接电流和较短的焊接时间,接头熔合不良;焊接电流太大,焊接过程中飞溅很大,焊点表面压痕深度超标,同时形成方向性很强的粗大柱状晶;适当增加电极压力,可使柱状晶发生倾斜,方向性减弱.研究确定了0.8mm厚镀铝锌钢板较佳的工艺参数为I=8.5～9.0 kA,T=14cyc,FW=2 400 N,用这组工艺参数焊接,点焊接头抗剪力、熔核直径均超过了<点焊焊接区的检验方法>标准中规定的A级要求,熔透率、焊点表面压痕深度均能满足质量要求.