Heat flux affected by current increment ratio in pulsed arc mixed oxygen

Abstract

Summary form only given. Gas tungsten arc (GTA) welding is a high-quality joining technology. However, the GTA welding cannot melt the welding pool deeply. Therefore, the weld defect sometimes occurs because of this poor heat transfer to the anode and ability of melting deeply. The welding parameter should be controlled in order to improve the welding productivity and prevent the weld defect. The pulsed arc welding has been developed because it can control the heat transfer with the current waveform. In the case of high frequency, the width of the welding pool decreases and the welding depth increases because of increment of the heat flux and electromagnetic force of welding pool. However, it is expected that depth is not enough only by using a pulsed current under any conditions. The shielding gas species and current contribute to the depth. In particular, the heat flux increases when the dissociative gas such as the oxygen is mixing. Because the temperature distribution is changed by the specific heat at a low temperature increment. Thus, the heat flux increased with the shielding gas species and pulsed current. However, few reports have considered them. In this research, the heat flux affected by the current increment ratio in pulsed arc welding mixed oxygen was elucidated. The temperature and the current density, energy balance of the arc were elucidated the increment of the heat flux. As a result, the heat flux to the anode increases when the current increment ratio increases. Therefore, the current increment ratio plays important role for making welding pool in pulsed arc welding mixed oxygen.