Effect of Arc Current Ultrasonic-frequency Pulsation on Underwater Wet Arc Welding Quality

A novel process of ultrasonic-assisted underwater wet arc welding was proposed to improve the joint properties, a number of ultrasonic-assisted underwater welding experiments were then carried out, and the effects of pulse frequency on weld formation, joint hardness and microstructure were investigated. Experimental results show that the ultrasonic frequency pulsation of arc can improve weld penetration while reducing effectively the hardness of joint HAZ in the arc axial direction and refining the grain of microstructure, and the effects of which are related closely to the pulse frequency.