There is stress in the steel pipe, no matter where it is, it will cause the steel pipe to crack during quenching. Generally, in the production process, after the heat treatment, a cooling process is required. If the cooling is too fast or incomplete, it will also cause cracks on the surface of the steel pipe.

During the welding of large-diameter thick-walled pipes, the workpiece and the solder melt to form a molten area, and the molten pool is cooled and solidified to form a connection between the materials.

According to different production methods, manufacturing methods can be divided into hot-rolled tubes, cold-rolled tubes, cold-drawn tubes, and extruded tubes.

Encapsulate high-density high-pressure polyethylene raw materials on the outer surface of seamless pipes, which have very high impact toughness and high-quality corrosion resistance, and can protect them from external factors during the entire process of transportation, installation and application. The destruction caused by the element.

Thermally expanded seamless steel pipes are widely used in aerospace, chemical plants, engineering construction, food, industrial control systems, pharmaceuticals, nuclear power plants, gas development, design, production, manufacturing, transportation, and deep-sea surveys.

The remaining stress will inevitably occur in the welding seam during the forming and welding process, so the remaining stress should be eliminated after the tube blank is formed and welded. Diameter expansion can eliminate the remaining stress, but it is difficult to completely eliminate the remaining stress, and it is impossible to eliminate the remaining stress at the weld toe.