1. The general boiler tube operating temperature is below 350 ℃, and the domestic tubes are mainly made of No. 10 and No. 20 carbon-bonded steel hot-rolled tubes or cold drawn tubes. Mainly used to manufacture water-cooled wall pipes, boiling water pipes, superheated steam pipes, superheated steam pipes for locomotive boilers, large and small smoke pipes and arch brick pipes, etc.
2. High-pressure boiler tubes are often in high-temperature and high-pressure conditions when used, and the tubes will oxidize and corrode under the action of high-temperature flue gas and steam. The steel pipe is required to have high endurance strength, high resistance to oxidation and corrosion, and good organizational stability. High-pressure boiler tubes are mainly used to manufacture superheater tubes, reheater tubes, gas guide tubes, main steam tubes, etc. of high-pressure and ultra-high-pressure boilers.

(1) High-quality carbon structural steel grades are 20G, 20MnG, 25MnG.
(2) Alloy structural steel grades 15MoG, 20MoG, 12CrMoG, 15CrMoG, 12Cr2MoG, 12Cr1MoVG, 12Cr3MoVSiTiB, etc.