Design of high-manganese medium-thickness plate applied to LNG (Liquefied Natural Gas) storage tanks and production method thereof

Abstract

The invention relates to design of a high-manganese medium-thickness plate applied to LNG (Liquefied Natural Gas) storage tanks and a production method thereof and belongs to the field of steel materials. The high-manganese medium-thickness plate comprises the following chemical components in percentage by weight: 0.45-0.67% of C, 0.02-0.48% of Si, 23.70-27.20% of Mn, less than or equal to 0.051% of P, less than or equal to 0.02% of S, 0.00-2.20% of Ni, 0.00-4.13% of Cr, 0.00-1.10% of Cu, 0.00-0.94% of Mo, 0.00-0.21% of V, 0.00-4.64% of Al and the balance of Fe and inevitable impurities. The production method of the high-manganese medium-thickness plate comprises the steps of smelting, pouring, forging and rolling. The product obtains a single-phase austenite structure; the experiment steel has high plasticity, simultaneously obtains excellent impact toughness at ultralow temperature of 196 DEG C below zero and has potential for replacing 9% Ni steel; and the cost of the experiment steel is far lower than that of the 9% Ni steel.

Description

technical field [0001] The invention relates to a design and a manufacturing method of a high manganese plate for an LNG storage tank, and belongs to the field of iron and steel materials. Background technique [0002] In recent years, LNG (liquefied natural gas, Liquefied Natural Gas), as a high-quality and efficient clean energy, has received more and more attention at home and abroad, and has already met the conditions for marketization. As the cleanest non-renewable energy recognized by the world, the production of LNG in my country is like a prairie fire, and it is rapidly entering the "golden age" of large-scale and industrialization. At present, there are 12 countries (about 68 production lines) producing LNG in the world, with a production capacity of 138 million tons per year. LNG products have been widely used in power generation, chemical raw materials, new vehicle fuels, civil fuels and other fields. [0003] It is estimated that natural gas will account for 25%...

AI Technical Summary

Problems solved by technology

Although there is no obvious ductile-brittle transition phenomenon in high-Mn austenitic steel, the Mn segregation and carbide precipitation at the grain boundary greatly weaken the grain boundary strength, leading to intergranular cracking and significantly reducing the ultra-low temperature impact absorption energy at -196 °C

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