薄板铝合金空间曲线焊缝CMT焊接试验研究

摘要

针对薄板铝合金三维曲线焊缝较大的残余应力和焊接变形，进行了冷金属过渡（CMT）无垫板自动焊试验研究，分析了电流、焊接速度、弧长修正、保护气流量对焊接过程的影响，进行了接头拉伸性能试验及焊缝微观组织研究，并焊接了变形小的产品。结果表明，利用合理的焊接参数，可实现厚度1．5 mm的5 A06铝合金的无垫板CMT焊接，焊缝成形稳定均匀，焊接接头抗拉强度值达到347 MPa，接头断裂位置在热影响区。无垫板CMT焊接技术可用于薄板铝合金空间曲线焊缝的焊接。%For the higher residual stress and distortion of aluminium alloy sheet with three-dimensional curve weld,no-liner plate auto-welding was studied.The effect of current,speed,arc voltage,gas flux were investigated.The tensile performance and microstructure of joint were determined.The product with little weld distortion was manufactured.The results show that 1 .5 mm thick 5 A06 aluminium alloy three-dimen-sional curve weld can be achieved by reasonable no-liner plate CMT parameters.The weld shape is stable and uniform,tensile strength reached 347 MPa,fracture occurred in HAZ.No-liner plate CMT welding technology can be used in space curve welding for the aluminium alloy sheet.