Tempering is a heat treatment process in which a 20G high-pressure boiler tube quenched into martensite is heated to a temperature below the critical point, held for an appropriate time, and then cooled to room temperature.

Large-diameter thick-walled straight seam steel pipes are distinguished from small-diameter steel pipes. In fact, large-diameter steel pipes are mainly used in the pipeline industry, and these are used for work on some construction sites.

From the point of view of the welding process. Regardless of whether it is a straight seam steel pipe or a spiral steel pipe, the welding method of the two is the same.

Squeeze amount refers to the amount of metal squeezed at the weld when the edge of the tube passes through the squeeze roll after high-frequency heating.

Under certain other conditions, increasing the welding speed will reduce the welding heat input, thereby reducing the weld width and penetration. Since the amount of welding wire metal deposition per unit length of the weld is inversely proportional to the welding speed, it also leads to The weld reinforcement is reduced.

Low temperature seamless steel pipe are mainly used in the production of ethylene, propylene, urea, synthetic ammonia, compound fertilizers, and other process equipment.