High-pressure boiler tubes: high-quality carbon structural steels, alloy structural steels and stainless steel seamless steel tubes for steam boiler piping, which are mainly used to manufacture high-pressure and above pressure, and which are often under high temperature and high pressure, tubes in the high-temperature flue gas and water vapor will also occur oxidation and corrosion, so that the steel pipe has a high durability, high antioxidant performance, and has good organizational stability, the use of steel number: High quality carbon structural steel number 20G, a106b, a106c Alloy Structural steel number 15MoG, 20MoG, 12CrMoG, 15CrMoG, 12cr2mog, 12CR1MOVG, 12cr3movsitib and so on; stainless steel commonly used 1cr18ni9, 1cr18ni11nb high-pressure boiler tube In addition to the chemical composition and mechanical properties to ensure that the root of the water pressure test, to be expanded, flattening test. The steel pipe is delivered in heat treatment condition. High-pressure boiler tube specifications and appearance of quality: GB5310 "high-pressure boiler seamless steel tube" hot-rolled pipe outside the outer diameter 22~530mm, wall thickness 20~70mm unequal. Cold (cold-rolled) pipe diameter 10~108mm, wall thickness 2.0~13.0mm range.
1, Manufacturing methods:
① General Boiler tube temperature under 450 ℃, domestic pipe mainly used 10th, 20th carbon steel hot-rolled pipe or cold drawn pipe manufacturing.
② high-pressure boiler tubes are often in high temperature and high pressure conditions, the pipe in the high-temperature flue gas and water vapor, will occur oxidation and corrosion. It is required that the steel tube has high durability, high pressure-resisting corrosion alloy high-pressure boiler tube high pressure boiler tube, and has good microstructure stability.
① General boiler tube is mainly used to manufacture water-cooled wall tubes, boiling water pipes, superheated steam pipes, superheated steam pipes for locomotive boilers, large, small smoke pipes and arch brick pipes.
② high-pressure boiler tube is mainly used to manufacture high pressure and ultra-high pressure boiler superheater tube, reheater tube, guide pipe, main steam pipe, etc.
3, the boiler tube uses the steel number
(1) High-quality carbon structural steel number 20G, a106b, a106c.
(2) Alloy structural steel number 15CrMoG, 12cr2mog, 12CR1MOVG, P91, T91, 12cr3movsitib and so on.
(3) Rust-resistant steel 1cr18ni9, 1cr18ni11nb boiler tube In addition to the chemical composition and mechanical properties to ensure that the root of the water pressure test, to be expanded, flattening test. The steel pipe is delivered in heat treatment condition.
In addition, the microstructure, grain size and decarbonization layer of the finished steel pipe are also required.