药芯钎料CMT熔钎焊铝/钢焊接接头的组织和力学性能研究

Study on Microstructure and Mechanical Properties of Aluminum/Steel Joint Welding-Brazed by CMTT With Flux-cored Wire

以AlSi5药芯钎料为填充金属,进行6082铝合金与Q235钢CMT(冷金属过渡)熔钎焊试验研究,对不同焊接速度下焊接接头的微观组织和力学性能进行了分析。结果表明:AlSi5药芯钎料中钎剂提高了熔融的铝合金在Q235钢表面的润湿铺展性能。6082铝合金/Q235钢界面层组织中有Fe2Al5和Al8Fe2Si生成。随着焊接速度从450mm/min增加到550 mm/min,铝合金/低碳钢界面层厚度逐渐减小,焊接接头的抗拉强度先增加后减小。当焊接速度为500 mm/min时,抗拉强度达到最大值,为159MPa。

The CMT(cold metal transition)welding-brazing of 6082 aluminum alloy and Q235 steel with AISi5 flux-cored wire was carried out.The microstructure and mechanical properties of the welded joints at different welding speeds were analyzed.The results show that the flux of AiSi5 flux-cored wire improves the wettability of the molten aluminum alloy on the surface of Q235 steel.Fe2Als and Al.Fe,Si intermetallic compounds are formed at the interface layer between 6082 aluminum alloy and Q235 steel.Meanwhile,with the increase of welding speed from 450 mm/min to 550 mm/min,the thickness of the interface layer between aluminum alloy and low carbon steel decreases gradually,and the tensile strength of the joint increases first and then decreases.When the welding speed is 500 mm/min,the tensile strength is up to the maximum of159MPa.