Low-Ni high-Mn economical low-temperature steel capable of being used at minus 196 DEG C and preparing method thereof

Abstract

The invention discloses low-Ni high-Mn economical low-temperature steel capable of being used at minus 196 DEG C and a preparing method thereof. The low-Ni high-Mn economical low-temperature steel capable of being used at minus 196 DEG C and the preparing method thereof solve the problem that existing low-temperature steel is high in technological difficulty and high in cost. The low-temperature steel comprises, by weight, C<=0.04, Si<=0.05, Mn:1.00-1.50, P<=0.005, S<=0.003, Alt:0.015-0.050, Ni:7.00-8.00, Nb:0.02-0.05, Ti:0.008-0.025, N<=0.004, at least one of Mo<=0.35, Cu<=0.20 and Ca<=0.005, and the balance Fe and inevitable impurities. The preparing method comprises the steps of smelting, rolling and drawing. The steel prepared with the method is good in toughness and welding performance after composition design, impurity control, rolling and heat treatment and can be used for manufacturing pressure vessel equipment requiring low-temperature usage in the LNG industry, and production difficulty and cost are effectively reduced.

Description

technical field [0001] The invention relates to a low-temperature steel and a manufacturing method thereof, in particular to a low-Ni and high-Mn economical low-temperature steel applicable to -196°C and a manufacturing method thereof, mainly used in the manufacture of LNG low-temperature storage tanks. Background technique [0002] With the diversification of global energy resources and the increasing emphasis on environmental protection, natural gas, as a clean energy, will occupy an increasing proportion in the future. Since the storage and transportation temperature of liquefied natural gas is below -162°C, it is required that the materials used to store liquefied natural gas have good low-temperature toughness, strength, and sufficient resistance to brittle cracking and crack arrest at ultra-low temperatures. [0003] At present, the materials used in the LNG storage and transportation equipment built in the world are mainly 9Ni steel with a Ni content of about 9%. Bef...

AI Technical Summary

Problems solved by technology

At present, nickel-based low-temperature steel is used for this type of device in China, but the low-temperature steel that meets the requirements for use at -196°C has a high nickel content (above 9.0%), and the production cost is too high

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