Cracks after Welding or during Welding

Because long-distance natural gas pipelines have long distances and complicated geographical environments, there are many factors that affect the normal operation of pipelines, but the most important factors can be divided into the external environment and the quality of the pipeline itself. The quality of steel pipes is the most important factor affecting the quality of steel pipes, and the main aspects of the quality of steel pipes include the manufacturing process of high-quality steel pipes using steel pipes and steel pipes.


Incomplete fusion between the filler metal base or the filler metal does not fill the metal between the fusions. Improper welding pool, high drawing speed, too small welding current, improper electrode angle, etc. are the main causes of welding failure. Slag: Residual residue in weld metal or non-metallic inclusions. The main reason for the slag is that the welding current is too small, the welding speed is too fast, clean and the non-metallic inclusions float in the slag or too late. Cracks are the heat affected zone of a weld or a partially broken hole during welding or welding. According to the causes of cracks can be divided into hot cracks, cold cracks and reheat cracks. Thermal cracking is caused by improper welding process. The main reasons that hinder high-frequency straight seam welded pipe are the deterioration of high-speed welding seams, the influence of undercuts, and the control of welding process parameters and external shapes. The use of double wire submerged arc welding wire (or above) is a reasonable method of welding, which can not only guarantee the quality of welding but also effectively increase the welding speed. Therefore, the solder joint should be at the offset distance between the top of the steel and the reverse rotation so that the weld pool is close to the horizontal position to obtain a good weld shape.