【摘要】 采用高压环境模拟舱对高压干法熔化极气体保护焊(gas metal arc welding,GMAW)进行了试验研究.焊接电源采用数字增量型PID算法,在常压下进行控制器系数整定.通过试验获得了环境压力为0.4,0.8,2 MPa时焊接电弧弧柱区的电场强度,理论推导了压力环境电弧特性的改变对焊接电源控制品质的影响规律,并将环境压力作为变量引入到控制器算法中.采用常压下整定的控制器系数,在环境压力为0.8 MPa时,对算法改进前后进行了试验验证.结果表明,改进后的焊接电源控制算法能够有效减少焊接电流的波动,从而提高了焊接过程稳定性,使焊接过程产生的飞溅尺寸和数量有所改善.更多还原

【Abstract】 Experimental research is carried out by using hyperbaric chamber and welding power source with opening control system. The power source is based on incremental digital PID,which coefficients are set at normal pressure. The electric field intensity of welding arc column is obtained by experiments at ambient pressure of 0. 4 MPa,0. 8 MPa and 2 MPa,respectively. The effect of arc charactarasics change on welding power control quality is derived. Based on these results,the ambient pressure,as a variable,is added to the welding power control algorithm. The verification test is conducted at 0. 8 MPa ambient pressure using the previous controller coefficients. The results show that the welding current fluctuation is reduced with the improved control algorithm,the stability of welding process is improved with better spatter.更多还原