28.7. Lack of fusion and incomplete penetration defects?

During the welding process, there is a part of the steel plate that has no tendency to melt with the welding rod, which can lead to defects such as incomplete penetration or lack of fusion during welding. The incomplete penetration defect mainly occurs at the root of the welded joint, especially when the thickness of the steel plate is larger, making the incomplete penetration phenomenon more obvious. In the welding process of spiral steel pipes, the lack of fusion may occur in any part of the weld. It can be seen that the incomplete penetration and lack of fusion defects are the main defects in the production of spiral steel pipes, which will result in a sharp decline in the overall quality of the steel pipe, thereby affecting its normal use.