Manufacturing method of high-quality P92 large-aperture thick-wall seamless steel pipe of ultra-supercritical unit

Abstract

The invention relates to a manufacturing method of a high-quality P92 large-aperture thick-wall seamless steel pipe of an ultra-supercritical unit and belongs to the field of heat-resistant steel tubing manufacture. The manufacturing method realizes dynamic combination of internal control of steel chemical components, improvement of steel purity, steel ingot casting, enclosed upsetting, reverse extrusion punching, extrusion molding and spraying quenching, the steel tube obtained by the manufacturing method satisfies ASMESA335, EN10216-2 and GB5310 standard requirements, the microstructure of the steel tube is completely tempered martensite and satisfies the requirement of clear martensite lath orientation in the 400x view field, delta-ferrite content is less than or equal to 1% and less than or equal to 3% in the most serious field, and comprehensive performance indexes satisfy the international advanced level. The manufacturing method can produce different specifications of P92 large-aperture thick-wall seamless steel pipes having the external diameter of 325-1200mm, wall thickness of 20-180mm and length less than or equal to 12500mm, and can be used in different fields of an ultra-supercritical boiler and power-station four-pipes. The manufacturing method can effectively guarantee product quality and the high-quality P92 large-aperture thick-wall seamless steel pipe obtained by the manufacturing method can replace an imported product.

Description

technical field [0001] The invention relates to a high-quality P92 large-caliber thick-wall seamless steel pipe for an ultra-supercritical unit and a manufacturing method thereof, belonging to the field of heat-resistant steel pipe manufacturing. Background technique [0002] The development of large-capacity and high-parameter units, especially ultra-supercritical (USC) units, will be the inevitable trend of thermal power generation in my country to "improve power generation efficiency, save primary energy, improve the environment, and reduce power generation costs". In order to improve the efficiency of thermal power units, reduce coal consumption, protect the environment and reduce CO 2 In the future, new thermal power units will be mainly large-capacity and high-efficiency units. At present, my country has become the country with the largest number of ultra-supercritical units in the world. A 1000MW unit (including the ultra-supercritical steam boiler and the four majo...

AI Technical Summary

Problems solved by technology

Imported materials are expensive, and the supply cycle is difficult to guarantee, resulting in higher manufacturing costs for boilers and power stations, and longer construction periods for power plants, which seriously restricts the country's power construction

In particular, domestic and foreign literature shows that "when the heating temperature exceeds 1200 °C, the δ-ferrite content in the finished steel will increase significantly, which will affect the mechanical properties of the steel pipe", which further increases the difficulty of manufacturing P92 steel pipes.

Images