Low-temper-brittleness Cr-Mo steel plate for high temperature resisting pressure-bearing equipment and preparation method of steel plate

Abstract

The invention discloses a low-temper-brittleness Cr-Mo steel plate for high temperature resisting pressure-bearing equipment and a preparation method of the steel plate. The steel plate comprises the following chemical components in percentage by weight: 0.05-0.17 percent of C, smaller than or equal to 0.30 percent of Si, 0.40-0.65 percent of Mn, smaller than or equal to 0.035 percent of S, smaller than or equal to 0.015 percent of P, 0.80-1.15 percent of Cr, 0.45-0.60 percent of Mo, smaller than or equal to 0.005 percent of Sn, smaller than or equal to 0.005 percent of Sb, smaller than or equal to 0.005 percent of As and the balance of Fe and trace of impurities. By composite addition of Cr and Mo alloy elements, reasonable Si and Mn content design, strict control on low P content and extremely low residual element Sn and implementation of technologies of 4300mm double-frame rolling, normalization, high-temperature tempering and the like, the steel plate for the high temperature resisting pressure-bearing equipment can be obtained. The steel plate has the characteristics of being low in temper brittleness coefficient and mechanically stable, lasting in high temperature in a core part of a thick-specification steel plate, high in mechanical properties and the like, and is suitable for manufacturing high temperature pressure-bearing equipment.

Description

technical field

[0001] The invention relates to the technical field of iron and steel, in particular to a low temper brittle Cr-Mo steel plate for high-temperature resistant pressure-bearing equipment and a preparation method thereof. Background technique

[0002] Cr-Mo series steel plates for pressure equipment are widely used in the manufacture of pressure equipment such as hydrogenation reactors, ammonia synthesis units, and urea cooperation units. The equipment has been in service for a long time under harsh conditions of high temperature and high pressure. This type of steel tends to be brittle in the temperature range of 350-600°C, which will lead to the aging of the manufacturing materials and cause safety accidents. For this reason, steel plates for Cr-Mo pressure-bearing equipment for high temperature resistance generally have clear requirements for the J coefficient and X coefficient that characterize the tendency of temper brittleness.

[0003] The published pate...