Crack Control Technique of CO2 Flux Cored Arc Welding

LI Ke-jie

（ Shanghai Branch, NIPPON KAIJI KYOKAI (China) Co., Ltd., Shanghai 200336, China）

Abstract: The cause of the first layer longitudinal welding crack in CO2 flux cored arc welding (FCAW) is discovered through experiment. With the experience accumulated from on-site construction and inspection, it found that the key point to control the first layer welding crack is to control the current for welding. The safe welding parameters are thus given out, and the first layer welding crack is effectively controlled through the self-control of the shipyard. At the same time, the difference between the first layer welding cracks is pointed out for flat welding and horizontal welding. It further proves that gouging the cracks is an effective way to remove large area of first layer welding cracks.

Key words: CO2 flux cored arc welding; first layer welding; crack; welding current; welding parameter