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为了研究气压降低对电弧特性的影响,对不同大气压情况下的焊接工艺数据进行研究和机理分析。研究结果表明:自保护药芯焊丝的电弧静特性呈下降趋势;随着焊炬高度(电弧长度)的增加,电弧静特性曲线上移。在低气压环境下,电弧空间的气体密度和温度降低,导致导电粒子密度降低,焊接电流减小;焊接电弧的扩展,导致弧柱直径增大、电场强度降低,但阴极和阳极压降增加,仍使总电弧电压增加。由于低气压时的弧柱电场强度降低,电弧的自身调节能力减弱,电弧稳定性和弧柱挺度下降,从而影响焊缝成形和接头质量。在低气压地区进行自保护药芯焊丝电弧焊接时,必须严格控制焊接工艺参数,尽可能采用低电弧电压进行焊接。
In order to study the effect of pressure drop on the arc characteristics, the welding process data under different atmospheric pressures were studied and analyzed. The results show that the arc static characteristics of self-shielded flux cored wire show a decreasing trend. With the increase of torch height (arc length), the arc static characteristic curve shifts upward. Under low atmospheric pressure, the gas density and temperature decrease in the arc space, resulting in the decrease of the density of the conductive particles and the decrease of the welding current. The expansion of the welding arc leads to the increase of the diameter of the arc column and the decrease of the electric field intensity, Still make the total arc voltage increase. Due to the decrease of the electric field intensity of the arc column at low pressure, the self-regulation ability of the arc is weakened, the stability of the arc and the stiffness of the arc column are decreased, which affects the formation of the weld and the quality of the joint. In low pressure areas for self-shielded flux cored wire arc welding, the welding process parameters must be strictly controlled, as far as possible the use of low arc voltage welding.