浅水湿法和常压空气中焊接的电弧稳定性

Arc Stability of Shallow-Wet and Atmospheric In-Air Welding

由于水和压力对焊接过程的影响,浅水湿法焊接的电弧稳定性较差.为此,文中提出以焊接电弧电压差异系数的倒数作为衡量电弧稳定性的指标,利用高压舱水下焊接平台进行湿法焊接试验,通过采集不同焊接参数下湿法和空气中焊接的电压波形并计算焊接电压差异系数的倒数,定量研究了浅水湿法和常压空气中药芯焊丝焊接电弧的稳定性.结果表明,在所试验的焊接参数范围内,浅水湿法焊接的电弧稳定性与电流呈负相关,与电压呈正相关,故应选择最优的导电嘴至工件距离以使电弧稳定性最高;浅水湿法焊接的电弧稳定性随焊接速度的增大而减小,而常压空气中焊接基本不变;湿法焊接可采用的焊接电压和电流的工艺参数窗口更窄;焊接电流一定时,湿法焊接应比空气中焊接选用更高的电压,以提高焊接电弧的稳定性.

In order to overcome the low stability of the underwater wet welding due to the effect of water and pressure, the reciprocal of the difference coefficient of arc voltage was taken as the measurement index of arc stability, and some wet welding experiments were carried out in an underwater hyperbaric chamber. Then, according to the reciprocal of the difference coefficient as well as the voltage waveforms of the wet and the in-air welding at different parameters, the arc stability of shallow-wet and in-air flux-cored arc welding was quantitatively discussed. The resuits show that, within the range of welding parameters in the experiments, the arc stability of wet welding has a negative correlation with the current but a positive correlation with the voltage, and the CTWD value should be optimized to achieve the maximum arc stability. Moreover, it is found that the arc stability of underwater shallow-wet welding degrades with the increase of welding speed, while that of atmospheric in-air welding almost keeps un- changed, that the wet welding is of narrower range of acceptable welding parameters, and that higher welding voltage should be selected in wet welding for the purpose of improving the arc stability at constant welding current.