冷金属过渡条件下4043铝合金在不同钢板上的润湿行为

Wetting behavior of molten 4043 aluminum alloy on different steel plates in cold metal transfer

关键词:  铝-钢异种金属  冷金属过渡  润湿性

Key words:  aluminum/steel dissimilar metals  cold metal transfer  wettability

摘要:

采用激光背光投影技术研究了冷金属过渡条件下4043铝合金分别在Q235钢板和镀锌钢板表面的润湿行为及其与工艺参数的关系,同时分析了镀锌层的作用. 结果表明,铝-Q235钢在CMT条件下的润湿行为与焊接工艺参数中的送丝速度v和点焊时间t密切相关,具体可以表达为:v≤4 m/min时θ(t)=θ₀+2(54-10v)(1-exp[(0.33-3v)t]),v>4 m/min时θ(t)=θ₀+(58-7v)exp[-(1.7-0.15v)t]. 铝-Q235钢、铝-镀锌钢在较大热输入的情况下两者都可以达到较好的润湿性. 锌蒸汽将导致工艺不稳定,主要归结于液-固界面上的锌蒸汽阻隔了熔滴与母材的接触.

Abstract:

The wetting behavior of molten 4043 aluminum alloy on the surface of different steel plates and the relationship of wetting behavior and process parameters during cold metal transfer welding were investigated by using laser backlight technology. The role of zinc coating of galvanized steel in the wetting process was further analyzed. The results show that the coupling relationship of wetting behavior of molten Al 4043 alloy on Q235 steel in CMT process can be expressed as δ(t)=δ₀+2(54-10v)(1-exp[(0.33-3v)t] (when v≤4 m/min), and δ(t)=δ₀+(58-7v) exp [-(1.7-0.15v)t] (when v > 4 m/min). Good wettability was observed when the heat input was large whether the used substrate was Q235 steel or galvanized steel. Zn vapor induced the instability of metal transfer process, because the Zn vapor on the interface cut off the contact of molten droplet and base metal.