Relationship between welding speed and welding quality
The relationship between welding speed and weld quality should be understood dialectically and cannot be ignored. It is mainly reflected in the heating stage and the crystallization stage. 1. Heating stage Under the condition of high-frequency straight seam welded pipe (erw pipe), the edge of the tube blank is heated from room temperature to the welding temperature. During this process, the edge of the tube blank is completely exposed to the air without any protection, which must be violent with oxygen and nitrogen in the air. reaction, resulting in a significant increase in nitrogen and oxides in the weld. It is determined that the nitrogen content in the weld increases by 20-45 times, and the oxygen content increases by 7-35 times. At the same time, a large number of alloying elements such as manganese and carbon that are beneficial to the weld are burned and evaporated, resulting in a decrease in the mechanical properties of the weld. Therefore, in this sense, the slower the we...