Stability analysis of the gas metal arc welding process based on acoustic emission technique

摘要

A new criterion for stability analysis of the gas metal arc welding (GMAW) process is proposed and presented in this work, based on acoustic emission generated by the arc during short-circuiting metal transfer. For the experimental development an AWS ER70S-6 wire with a diameter of 0.8 mm and a DEP 401 rectiier were used. The weld bead was carried out on a 4-mm-thick AISI 1020 steel plate. Several welding conditions were studied with variation of the process parameters during the deposition of the beads. The acoustic emission signals were acquired using a measurement system composed of a MV-201 microphone, with a sensitivity of 10 +- 3 mVPa~(-1) and frequency bandwidth of 20Hz to 170dB to 100kHz, and a data acquisition card coupled to a PC. A stability index was proposed. Eventually, a statistical analysis for validation of the obtained experimental results was carried out. The outputs allowed obtained a relationship between the acoustic signals and the arc voltage signals. The feasibility of the proposed index, and the effectiveness of the method as a novel means of analysing the stability of arc welding, was demonstrated based on acoustic emission for analyses of GMAW process stability.