摘要
An experimental setup to excite ultrasonic by modulating electrical arc was applied in the submerged arc welding （SAW） process of 09 MnNiDR steel to study its effect on quality of the welds. Arc-excited ultrasonic energy refines grains of the welds and more acicular ferrite （ AF） appears in the fusion zone. It also enhances impact toughness of the joints at -70 ℃ significantly. With the ultrasonic of 50 kHz, the toughness is improved by 47% in the fusion zone and by 82% in the heataffected zone （HAZ）. The fractography of welds shows that the fracture is changed from cleavage fracture to gliding fracture while applying ultrasonic vibration.
An experimental setup to excite ultrasonic by modulating electrical arc was applied in the submerged arc welding （SAW） process of 09 MnNiDR steel to study its effect on quality of the welds. Arc-excited ultrasonic energy refines grains of the welds and more acicular ferrite （ AF） appears in the fusion zone. It also enhances impact toughness of the joints at -70 ℃ significantly. With the ultrasonic of 50 kHz, the toughness is improved by 47% in the fusion zone and by 82% in the heataffected zone （HAZ）. The fractography of welds shows that the fracture is changed from cleavage fracture to gliding fracture while applying ultrasonic vibration.
基金
the National Natural Science Foundation of China （Grant No. 50375080）.
