High-pressure boiler seamless steel tubes are a type of seamless steel tube used in boilers (working pressure generally not exceeding 5.88 MPa, working temperature below 450℃). They are used in high-pressure boilers (working pressure generally above 9.8 MPa, working temperature between 450℃ and 650℃) and belong to the seamless steel tube category. The manufacturing method is the same as for high-pressure boiler seamless steel tubes, but there are strict requirements for the steel grade used. High-pressure boiler seamless steel tubes are frequently used under high temperature and high pressure conditions. Under the influence of high-temperature flue gas and steam, they will undergo oxidation and corrosion. Therefore, high-pressure boiler seamless steel tubes are required to have high creep strength, good resistance to oxidation and corrosion, and good structural stability. High-pressure boiler seamless steel tubes are mainly used to manufacture superheater tubes, reheater tubes, steam pipes, and main steam pipes for high-pressure and ultra-high-pressure boilers.
The general production standards for high pressure boiler seamless steel tubes are: Chinese National Standard GB/5310, American Standard ASME SA213, ASME SA335, etc. Commonly used materials include: Chinese standard materials: 20G, 15CrMoG, 12Cr1MoVG; American standard materials: P11, P22, P91, P92, T11, T22, T91, T92, etc.
Due to long-term operation under high temperature and high-pressure conditions, high pressure boiler seamless steel pipe will undergo creep, decreased plasticity and toughness, alteration of the original microstructure, and corrosion. High-pressure boiler seamless steel pipes should possess the following characteristics:
(1) Sufficient creep strength;
(2) Sufficient plastic deformation capacity;
(3) Minimal aging tendency and hot brittleness;
(4) Good resistance to oxidation, coal ash, high-temperature corrosion from natural gas, steam, and stress corrosion;
(5) Good microstructure stability and good processing performance.
High-pressure boiler seamless steel pipes are made from carbon steel, as well as pearlitic, ferritic, and austenitic stainless heat-resistant steels. To improve the thermal efficiency of thermal power generating units and reduce fuel consumption, countries worldwide are primarily developing large-capacity, high-parameter (high-temperature, high-pressure) thermal power units (above 1000MW). Steam pressure has increased to 31.5–34.3 MPa, and superheated steam temperature has reached 595–650℃, moving towards ultra-high pressure critical pressure. This places higher demands on high pressure boiler seamless steel pipes. Appearance quality: The inner and outer surfaces of high-pressure boiler seamless steel pipes are not allowed to have cracks, folds, rolling defects, scale, delamination, or hairline cracks. These defects must be completely removed. The removal depth must not exceed the negative deviation of the nominal wall thickness, and the actual wall thickness at the cleaned area must not be less than the minimum allowable wall thickness.
Threeway Steel is known as a professional supplier engaged in manufacturing and distributing a wide range of steel pipe, and our headquarter located the central part of China – Hunan and six associated factories throughout China.
Threeway Steel is known as a professional supplier engaged in designing, manufacturing and distribution of a wide range of steel products with the headquarter located the central part of China – Hunan and six associated factories throughout China.
Threeway Steel is known as a professional supplier engaged in designing, manufacturing and distribution of a wide range of steel products with the headquarter located the central part of China – Hunan and six associated factories throughout China.
Threeway Steel is known as a professional supplier engaged in designing, manufacturing and distribution of a wide range of steel products with the headquarter located the central part of China – Hunan and six associated factories throughout China.
Threeway Steel is known as a professional supplier engaged in designing, manufacturing and distribution of a wide range of steel products with the headquarter located the central part of China – Hunan and six associated factories throughout China.
