The Research Of High Frequency Gas Shielded Welding Equipment And ARC Behavior

With the development of industrial technology, welding quality requires increase, the process of the welding needs more strict and accurate, high-frequency pulse welding is an advanced welding technology method being given and promotion of a wide range of applications. High frequency pulse welding have strong electromagnetic pinch effect, penetration of large, the fluidity of molten pool are relatively strong, and it can improve the welding efficiency and quality and other advantages. This advanced welding method has been widely used in aviation、petroleum、chemical industry、machinery manufacturing and other sectors.In this paper, the two sets of chopper circuit are used to achieve the base current and the peak current, two sets of circuits can be individually adjusted and the duty cycle can be adjusted. Comparing with other circuit topology, the chopper circuit is simple and reliable, with higher dynamic response performance. Compared with conventional PWM mode to realize the pulse current, the alternate conduction diode and IGBT can achieve more high frequency pulse current, and construct a complete welding platform, it can realize the high frequency pulse MAG welding stably.The arc shape、droplet transition and weld appearance are researched based on the arc length control algorithm in different pulse frequency and peak current, which obtains some preliminary results.The results show that the electromagnetic contraction effect and the arc stiffness can be enhanced when high frequency pulse is added to common arc.Compared with the conventional gas shielded arc welding, the diameter of the arc is the case of the contraction when the peak current is 120 A and the pulse current of frequency are 10 kHz and 5kHz. At the frequency of the pulse current of 1kHz and 15 kHz, the arc shape is basically the same as the arc shape of the arc shape gas shielded arc welding. When the pulse current frequency is 5kHz, the peak-peak current is different, and the arc shape is the same as the conventional, but the number of the droplet transfer can be increased.