1, appearance defects: appearance defects (surface defects) is not with the aid of the instrument, from the workpiece surface can be found in the defect. The appearance of defects are common, undercut, sag and welding deformation, sometimes surface porosity and surface crack. The root of one side welding is not welded thoroughly.

2, porosity and slag

A, the porosity is the welding, the gas in the weld pool is not in the solidification of the metal before the escape, remnants of the weld in the formation of the hole. The gas may be melted B, slag inclusion slag is a phenomenon in the welding seam after the welding slag residue.

3, the crack of the weld in the atom is destroyed, the formation of a new interface and the gap called crack.

4, did not weld penetration of non penetration refers to the base metal of the metal is not melted, the weld metal is not into the human, the phenomenon of joint root.

5, the fusion is not the fusion of the weld metal and the base metal, or between the weld metal is not melted together with the defect. According to their location, not fusion can be divided into incomplete fusion and non fusion between layers of three kinds of root incomplete fusion.