长输管道混合气体保护自动焊的工艺研究

研究了管道气体保护自动焊的熔滴过渡形式和混合气体（Ar+CO2）的比例对焊接工艺的影响。保护气体随着CO2比例的增加，熔深在平焊位、立焊位、仰焊位也在相应增加，并且保护气体比例相同时，熔深H立焊＞H平焊＞H仰焊。分析了混合气体比例对管道的焊缝质量、焊接工艺参数和焊丝的熔化速度等方面的影响。结果表明，管道自动焊的混合气体最好为“富氩气体”，其中Ar占80%～85％。

Study on Mix-gas Auto-welding Process of Long Transportion Pipeline

The influence of mix-gas(Ar+CO2) proportion and the behaviors of droplet transition in mix-gas auto-welding process of long transportion pipeline to welding process were studied by the PAW-2000 welding machine.With the increaseof CO2 proportion,the fusion depth in horizontal position,Vertical position,and position also increases.When the proportion of field gas is similar,the fusion depth H >H >H.The effect of mix-gas(Ar+CO2) proportion on weld seam quality,welding process parameter and wire melting speed in pipeline auto-welding is analysised.The research results indicated that the mix-gas of pipeline automatic welding is the best for the argon-rich gas,which accounts for 80%～85% Ar.