Welding Method of Welded Steel Pipe

Commonly used welded steel pipes are divided into the following three types according to the welding process used in their production.

① Continuous furnace welding (forge welding) steel pipe: It is characterized by high production efficiency and low production cost, but the metallurgical combination of welded joints is not complete, the weld quality is poor, and the comprehensive mechanical properties are poor.

②Electric resistance welded steel pipe: It is characterized by high production efficiency and a high degree of automation. It does not require welding rods and welding flux during welding has little damage to the base metal, and has little post-welding deformation and residual stress. However, its production equipment is more complex, the equipment investment is high, and the requirements for the surface quality of the welded joints are relatively high.

③ Arc welded steel pipe: Its characteristic is that the welded joint achieves complete metallurgical bonding, and the mechanical properties of the joint can completely meet or approach the mechanical properties of the base metal. According to the different weld shapes, arc welded steel pipes can be divided into two types: straight seam pipes and spiral welded pipes; according to the different protection methods adopted during welding, arc welded steel pipes can be divided into submerged arc welded steel pipes and molten electrode gas protection Two kinds of welded steel pipes.