High low-temperature impact toughness thick steel plates for hydrogen-contacting equipment and production method thereof

Abstract

Disclosed are high low-temperature impact toughness thick steel plates for hydrogen-contacting equipment and a production method thereof. The production method includes the steps: firstly, smelting and casting; secondly, heating plate blanks at 1070-1210 DEG C and rolling the plate blanks according to a compression ratio of 2.7-6.4; thirdly, normalizing within an austenitization temperature range; fourthly, accelerated cooling with water for 4-15 minutes; and fifthly, tempering at 700-750 DEG C; and sixthly cooling, wherein the steel plates comprise, in weight percentage, 0.10-0.15% of C, 0.50-0.60% of Si, 0.40-0.60% of Mn, not more than 0.010% of P, not more than 0.003% of S, 1.25-1.50% of Cr, 0.45-0.65% of Mo, 0.08-0.18% of Cu, 0.07-0.17% of Ni, 0.020-0.045% of Al, not more than 0.003% of Sn, not more than 0.003% of Sb, not more than 0.003% of As, 0.0020-0.0070% of N, the balance of Fe and unavoidable impurities, low-pressure section water flow of a pressure quenching machine is 18-38m<3> / min, top-to-bottom water volume ratio of each steel plate is 1:1.0-1.3, and the surface temperature of the steel palate at an outlet of the pressure quenching machine is not more than 120 DEG C.

Description

technical field [0001] The invention relates to a thick steel plate for hydrogen-facing equipment with good low-temperature impact toughness and a manufacturing method thereof, in particular to a 14Cr1MoR thick steel plate (50-110mm) and a manufacturing method thereof with a 1.25Cr0.5Mo alloy system capable of meeting the requirements for hydrogen-facing equipment . Background technique [0002] In the petrochemical industry, 14Cr1MoR steel plates are often used to manufacture equipment such as coal gasification units and oil synthesis units. The service conditions of these equipment are usually high temperature, high pressure and hydrogen. In such a harsh working environment, the performance requirements for the 14Cr1MoR steel plate used to manufacture equipment are very high. Moreover, with the increase of my country's energy demand, petrochemical reactor equipment is developing in the direction of automation and large-scale, resulting in increasing reactor wall thickness...

AI Technical Summary

Problems solved by technology

However, as the thickness of the steel plate required by users continues to increase, the cooling rate of the steel plate, especially the cooling rate of half of the plate thickness, decreases, so that the structure of the ultra-thick 14Cr1MoR steel plate produced by the normalizing + tempering process has more coarse The pro-eutectoid ferrite structure reduces the strength of the steel plate, and at the same time the low-temperature impact toughness of the steel plate deteriorates

Especially after the simulated post-weld heat treatment, the low-temperature toughness of the steel plate drops greatly, which cannot meet the user's requirements

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