Cr-Mo low-alloy steel plate for pressure vessel and preparation method of Cr-Mo low-alloy steel plate

Abstract

The invention discloses a Cr-Mo low-alloy steel plate for a pressure vessel and a preparation method of the Cr-Mo low-alloy steel plate. The steel plate comprises the following components in percentage by mass: 0.14%-0.19% of C, 0.17%-0.35% of Si, 0.70%-0.90% of Mn, less than or equal to 0.020% of P, less than or equal to 0.008% of S, 0.10%-0.25% of Cr, 0.25%-0.35% of Mo, 0.015%-0.030% of Nb and the balance of Fe and inevitable impurities. The preparation method of the steel plate is characterized by comprising the following steps of conducting smelting and casting, specifically, primarily smelting molten iron and scrap steel to obtain primary molten steel, and then refining and casting the primary molten steel to obtain a casting blank; conducting rolling and water cooling, specifically, heating the casting blank to obtain a hot casting blank, and rolling and cooling the hot casting blank to obtain the steel plate; and conducting normalizing heat treatment, specifically, conducting normalizing heat treatment on the steel plate to obtain the steel plate. The steel is low in added alloy variety and content, the process is simple and easy to operate, and the steel plate has good strength and plasticity, impact toughness, thickness direction performance uniformity and high-temperature mechanical property.

Description

Technical field[0001]The present invention belongs to the technical field of steel sheet production, and more particularly to a steel sheet for a Cr-Mo low alloy high-performance pressure vessel.Background technique[0002]High temperature pressure vessel steel is an important material applied under high temperature conditions in metallurgy, oil and chemical industries, with high temperature strength, creep resistance and corrosion resistance. With the development of my country's national economy, the work parameters of boilers and pressure vessels will gradually increase, and the performance requirements of such materials will also be more stringent.[0003]According to incomplete statistics, my country has 1000-4000M3More than 100 large-scale blast furnaces, high energy consumption, and contaminated small furnaces will gradually be eliminated. The current national standard "Specification for the Design of Blast Furnace Ironmaking Process" has proposed a year of blast furnace generatio...

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Problems solved by technology

[0005] At present, there are many patents on high-performance pressure vessel steel, but there are generally shortcomings such as high alloy content, complicated process flow, and insufficient high-temperature resistance. The following briefly introduces several similar patents:

[0006] Chinese patent application CN 108425002 discloses "a preparation method of 12Cr2Mo1 hot-rolled container steel plate". The steel plate involved in this patent is produced by the process of controlled rolling + normalizing + tempering. The production process is more complicated than this application and the cost of heat treatment is higher

Moreover, the high-temperature performance of the steel plate is insufficient, and it cannot meet the service requirements in a high-temperature environment

[0007] The patent document of Chinese Patent Publication No. CN 103695782 discloses "a steel for a mobile pressure vessel with a tensile strength of 630MPa and its production method", which adds various alloying elements such as Ni, V, Ti, Cu, Cr, etc. , the production cost is high, and the high temperature mechanical properties are not mentioned, which cannot meet the service requirements in high temperature environments

[0008] Chinese patent application CN 108149134A discloses "a 12Cr2Mo1VR steel plate for high-temperature pressure vessels and its production method". V and Ni alloy elements are added, which has a high alloy cost, and the method of two quenching + one tempering is used in the production process, the process flow is complicated, and the cost of heat treatment is high

[0009] Chinese patent application CN 109112400 discloses "a heat-resistant 12Cr1MoVR steel plate for containers and its production method". %, and the steel plate involved in this patent is produced by the heat treatment process of normalizing + tempering, the cost of heat treatment is relatively high, and its high temperature mechanical properties are not mentioned

[0010] Chinese patent application CN 109112421 discloses "a pressure vessel steel 07Cr2AlMoR and its production method". The steel plate involved in this patent has a relatively high Cr content of 2.10-2.30%, and the steel plate involved in this patent adopts normalizing + tempering The heat treatment process is used for production, the heat treatment process is complicated and the cost is high, and its impact energy at room temperature is much lower than that of this application, and its high temperature mechanical properties are not mentioned

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