High-pressure boiler seamless steel tubes are often under high temperature and pressure when used. The tubes will be oxidized and corroded under the action of high temperature flue gas and water vapor. It is required that the steel pipe has high durability, high resistance to oxidation and corrosion, and good structural stability. High-pressure boiler seamless tubes are mainly used to manufacture superheater tubes, reheater tubes, air ducts, and main steam tubes for high-pressure and ultra-high-pressure boilers.
The special-shaped seamless steel pipe is a general term for seamless steel pipes of other cross-sectional shapes other than round pipes. According to the different shapes and sizes of the steel pipe section, it can be divided into equal-wall thickness shaped seamless steel pipes (code D), unequal-wall thickness shaped seamless steel pipes (code BD), and variable-diameter shaped seamless steel pipes (code BJ). Shaped seamless steel tubes are widely used in various structural parts, tools and mechanical parts. Compared with the round pipe, the special-shaped pipe generally has a larger moment of inertia and a section modulus, and has a greater resistance to bending and torsion, which can greatly reduce the structural weight and save steel.
Production method of boiler seamless tube
Boiler seamless tube is a kind of seamless tube. The manufacturing method is the same as that of seamless pipes, but there are strict requirements on the steel grades used in the manufacture of steel pipes. According to the operating temperature, it can be divided into general boiler tubes and high-pressure boiler tubes.
(1) Manufacturing method:
① Generally, the service temperature of boiler seamless pipe is below 450℃. Domestic pipes are mainly made of No. 10 and No. 20 carbon steel hot-rolled pipes or cold-drawn pipes.
②High-pressure boiler tubes are often in high temperature and high pressure conditions when they are used. The tubes will be oxidized and corroded under the action of high-temperature flue gas and water vapor. The steel pipe is required to have high enduring strength, high oxidation and corrosion resistance, and good organizational stability.
①General boiler seamless pipes are mainly used to make water wall pipes, boiling water pipes, superheated steam pipes, superheated steam pipes for locomotive boilers, large and small smoke pipes and arched brick pipes.
②High-pressure boiler tubes are mainly used to manufacture superheater tubes, reheater tubes, air guide tubes, main steam tubes, etc. of high-pressure and ultra-high-pressure boilers.