Q235镀锌钢与5052铝合金CMT焊接工艺

为了实现汽车工业中车体制造的轻量化,将厚度均为1 mm的镀锌钢板与5052铝合金薄板采用冷金属过渡熔钎焊方法进行搭接焊实验,研究了工艺参数对焊缝宏观形貌、焊接接头微观组织和力学性能的影响.结果表明,Ar气保护下焊接接头的最大抗拉强度为128 MPa,金属间过渡层硬度为179. 4 HV,厚度约为5. 04μm. CO_2气体保护下焊接接头最大抗拉强度可达133 MPa,金属间过渡层硬度为194. 6 HV,厚度约为5. 68μm. CO_2保护可以改善焊接接头软化现象,但需调整热输入来控制金属间过渡层厚度.

CMT welding technology of Q235 galvanized steel and 5052 aluminum alloy

In order to realize the lightweight manufacturing of car body in automobile industry, the lap welding experiments were carried out by the cold metal transition(CMT)fusion brazing method on both galvanized steel sheet and thin 5052 aluminum alloy sheet, both with the thickness of 1 mm. In addition, the influence of technological parameters on the macro morphologies of weld seam, microstructure and mechanical properties of welded joint was studied. The results show that the maximum tensile strength of welded joint under Ar gas protection is 128 MPa, the hardness of intermetallic transition layer is 179.4 HV, and the thickness of this layer is 5.04 μm. The maximum tensile strength of welded joint under CO₂ protection is 133 MPa, the hardness of intermetallic transition layer is 194.6 HV, and the thickness of this layer is about 5.68 μm. The CO₂ protection can alleviate the softening phenomenon of aluminum joint, but the heat input needs adjustment to control the thickness of intermetallic transition layer.