Closed-loop control of weld penetration in keyhole plasma arc welding

来源期刊：中国有色金属学报(英文版)2004年第1期

论文作者：陈强 孙振国 孙久文 王耀文

文章页码：116 - 120

Key words：plasma arc welding; penetrating force; plasma arc; penetration; closed-loop control

Abstract: To improve the penetrating ability and the welding quality of keyhole plasma arc welding, a novel penetration closed-loop control system was established. In the system, welding current and plasma gas flow rate were selected as adjusting variables. The wavelet method was used to detect penetration status from welding arc voltage in real-time. The control strategy of one-keyhole-per-pulse was adapted to fulfill stable and high quality welding process. Experimental results show that the developed system can apparently increase the penetrating force of plasma arc and keyhole plasma arc welding is realized successfully in stainless steel with 10 mm in thickness. Moreover, the disturbances of gradual change and break change from 3 mm to 6 mm in thickness are come over due to the good response property of the developed system.