The rapid cooling of steel pipes after rolling has obvious effects on the production of bearing steel pipes, reducing network carbides, improving the pearlite structure, and shortening the spheroidizing annealing time.

The forming technologies of large-size seamless pipe fittings mainly include: hot spinning, hot extrusion, hot piercing and rolling, and hot pushing and expanding.

This method includes the setting of the furnace temperature and holding time in two passes.

The temperature conditions of the two experiments are basically the same, but the length and force of the weld are different. In the bending test, the weld is located on the side of the main surface of the bend, while in the flattening test, the weld is perpendicular to the direction of load application.

The steel sleeve direct-buried thermal insulation pipe is suitable for high-temperature steam pipelines for central heating in cities and towns, as well as high-temperature thermal pipelines for petroleum, chemical, electric power and other industrial sectors.

The quality of the seamless steel pipe is directly affected by the quality of the tube blank. In order to ensure the quality of the seamless steel tube, the quality of the tube blank must be guaranteed first.