双丝埋弧焊在造船业的应用和探索

Research and application of double-wires submerged arc welding in shipbuilding industry

造船业采用高效的双丝埋弧焊法,在焊接线能量一定的条件下,针对性很强地匹配各焊接参数以获得符合规范要求的焊接接头,同时满足CCS有关焊接工艺认可要求,并适用于车间大生产。通过单、双丝焊接接头金相对比观察到熔池液体金属结晶角度方向产生很大变化,认为其原因在于焊接熔池的表面张力与温度为函数关系,熔池表面张力大小取决于熔池表面上的温度分布,而熔池表面张力是影响熔池内液体金属流动的主要驱动力,当大电压、小电流的后丝电弧叠加时的温度场形成新的热循环改变了整个熔池液体金属结晶角度方向,不同于单丝埋弧焊焊接电流熔深(熔深系数)和单丝熔池的观点。

The efficient double wires submerged arc welding process which was used in shipbuilding industry in certain range of heat input condition,that aceurately balance the various parameters for the welding joint according to related code,which welding procedure specification was approved by China Classification Society and fitting the requirement of volume-production in workshop. The obviously changing of molten pool liquid metal crystal angle direction was observed with comparing the single,double wires welding joint microstructure, the phenomenon was speculated as somehow logical function between the welding pool surface tension and temperature, welding pool surface tension depends on the size of the molten pool temperature distribution on the surface, and the surface tension of welding pool is the main driving force to affect the fluidity of liquid metal in the welding pool.When the temperature field from the arc of the superimposing second wire with the relative high voltage and low current cause the new thermal cycle, and transfer the whole molten pool liquid metal crystal angle direction.That is different to the view of single wire submerged arc welding current penetration depth （depth of penetration coefficient） and single molten pool.