Development And Experimental Study Of The On-Line Monitoring System For MAG Welding Pool

As a kind of important welding method, Metal Active Gas Arc Welding is widely used in the production of large structure parts.Many random defects may happen in the process.So the welding quality inspection has become an indispensable link. Traditionally the inspection is conducted after welding. It can only find the welding defects,the reason cannot be found.So it is difficult to enhance product yield rate. In this paper, for the problem of on-line monitoring of MAG welding quality, some related research on the on-line monito ring technology of welding pool is carried out, which makes great significance.By the analyzation of the welding procedure qualification?welding process and quality inspection process,a method for on-line monitoring of molten pool was put forward. A set of on-line monitoring system for molten pool was designed and built. Based on the monitoring system,the real-time acquisition, display and storage of welding current, arc voltage, sound signal and weld pool image is possible. A large number of experiments were carried out in the control variable method and the orthogonal experiments method.By analyzing the influence of welding parameters on the penetration, weld width and weld residual height, the welding current, arc voltage and welding speed are finally determined as the feedback regulation.In this paper, the parameters of welding current, arc voltage and sound signal are extracted and analyzed in time domain, and the characteristic parameters are obtained. And in this paper, the process flow and feature parameter extraction of weld pool image processing are studied, and the method of extracting the weld pool profile and calculating the characteristic parameters of weld pool is obtained.It lays foundation for the subsequent establishment of the relationship between the characteristic parameters and the weld shape and weld quality.