电源电压对水蒸气保护焊短路过渡过程的影响

水蒸气保护电弧焊由于其独有的特性，在工程上有一定的替在应用价值，但是它存在与CO2焊相似的焊接工艺问题，如飞溅大、焊缝成影差等。实验发现，在送丝速度给定的情况下，匹配合适的电源电压可得到较好的焊接效果。利用燃弧阶段的焊丝熔化模型和短路过渡液桥失稳模型分析了电源电压对短路开始时液桥长度，以及短路过程中液桥失稳颈缩时的电流和所需时间的影响规律．从而可以解释水蒸气保护电弧焊在电源电压合适时可使短路峰值电流降低和短路时间缩短。从而使焊接过程稳定、飞溅减少。模型计算结果可用于指导正确选择焊接规范。

Effects of voltage of power supply on the short-circuit transfer process in water vapor arc welding

Water vapor arc welding has potential applications in engineering due to its unique features,similar to CO2 arc welding,it has same disadvantages such as metal spatter,bad appearance of weld,etc.It has been shown by experiments that the good welding effects can be obtained by matching proper voltage of power supply when a certain feeding wire speed is given.By using an electrode melting model during arc period and instability pinch model for liquid bridge during short-circuit period,it shows the effect behavior of voltage of power supply on the length of liquid metal bridge at the beginning of short-circuit,and on the current and time at instability pinch of liquid metal bridge during short-circuit.Accordingly,this simulation can explain the reasons that only when proper voltage of power supply be provided,both peak current and time during short-circuit period can decrease,and the welding process is stable and metal spatter is small.This model is helpful to select welding specifications correctly.