High-toughness steel plate for low-temperature pressure vessel and manufacturing method thereof

Abstract

The invention discloses a steel plate used for a high-tenacity low-temperature pressure vessel and a manufacturing method thereof. Steel comprises the following chemical components including, by weight, 0.090-0.130% of C, not greater than 0.15% of Si, 1.40-1.80% of Mn, not greater than 0.012% of P, not greater than 0.004% of S, 0.27-0.45% of V, 0.010-0.020% of N, not greater than 0.020% of Alt andthe balance Fe and inevitable impurities; and meanwhile, V / C is greater than or equal to 3 and smaller than or equal to 4, and V / (C+Si) is greater than or equal to 1.2 and smaller than or equal to 3.The steel provided by the invention is high in strength and good in low-temperature impact toughness, the minus 60 DEG C KV2 is greater than or equal to 80 J, an excellent manufacturing material is provided for the low-temperature pressure vessel, a foundation is laid for enlargement and lightweight of the low-temperature pressure vessel, furthermore, the carrying efficiency of the movable pressure vessel is greatly improved, and the economic benefit of the movable pressure vessel is greatly increased.

Description

technical field [0001] The invention relates to low-alloy steel, in particular to a high-toughness steel plate for low-temperature pressure vessels and a manufacturing method thereof. Background technique [0002] The importance of refrigeration and cryogenic technology in modern industry and scientific research is increasing day by day, and the application of cryogenic equipment in the national economy is also becoming more and more extensive. The design of cryogenic machinery ultimately faces two problems, one is to select the appropriate material to be used to fabricate such a device, and the other is to perform strength calculations of the selected material under working conditions. Different from general engineering design, the selection of cryogenic equipment materials is largely restricted by the working conditions of low temperature and the mechanical constraints and physical properties of materials. Therefore, understanding the special properties of materials at lo...

AI Technical Summary

Problems solved by technology

Currently commonly used nickel-based low-temperature steels include 1.5Ni, 2.5Ni, 3.5Ni, 5Ni and other high-Ni-containing steels. Nickel-based low-temperature steels have the following problems: 1) Ni is a relatively expensive element, about 280,000 yuan / ton, Increased cost; 2) The cast slab of Ni-containing steel tends to form dense oxide scales that are difficult to remove when heated, which brings difficulties to the heating and rolling process

The disadvantage of this steel is that the pearlite content in the steel is more than 25%, and the low temperature impact toughness can only meet -40℃KV 2 requirements, and cannot meet the requirements of steel for low temperature below -70°C

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