【摘要】 在薄板铝合金变极性脉冲熔化极惰性气体保护焊中,采用全桥高压脉冲双向稳弧方式,研究了高压稳弧脉冲电压幅值、脉冲持续时间、脉冲触发时刻、基值电流对焊接电流过零稳定性的影响。在小基值电流过零时,稳弧脉冲电压比基值电流对焊接电流过零稳定性的影响大。焊接电流过零的稳定性与稳弧脉冲电压的上升率有关,稳弧脉冲电压上升率有一个临界区间,使焊接电流过零时不稳定,采用稳弧脉冲电压上升率判断焊接电流过零稳定性,能够为铝合金VP PMIG焊焊接电流过零再引燃提供有效、可靠的依据。更多还原

【Abstract】 Variable polarity pulsed MIG welding of thin sheet aluminum alloy is realized by full bridge bidirectional high voltage arc stabilizing method,and the influences of voltage amplitude of high voltage arc stabilizing pulse,pulse duration,pulse triggering time and background current on cross zero stability are also investigated.When small background current crosses zero,the influence of arc stabilizing pulse voltage on cross zero stabilityis is more than that of background current.The rise rate of arc stabilizing pulse voltage which influences the cross zero stability has a critical span,in which the arc is unstable when arc current crosses zero.Estimating the cross zero stability of VP PMIG through calculating the rate of arc stabilizing pulse voltage,it can offer an efficacious and credible warranty to the reignition of the cross zero welding arc of aluminum alloy VP PMIG.更多还原