Cryogenic vessel steel of minus 110 DEG C and manufacturing method thereof

Abstract

The invention provides cryogenic vessel steel of minus 110 DEG C, the steel is formed by components, by weight, C 0.06%-0.10%, Si 0.20%-0.30%, Mn 0.60%-0.90%, P less or equal to 0.010%, S less or equal to 0.005%, Ti 0.010%-0.020%, Ni 2.1%%-2.5%, Cr 0.10%-0.30%, Al 0.020%-0.040%, Nb 0.020%-0.050%, and the rest is Fe and unavoidable impurities. The cryogenic vessel steel uses the processes of two-stage controlled rolling, control cooling and reasonable heat processing, a produced steel plate microstructure is formed by ferrite + tempering sorbite, the yield strength is big than 500 MPa, and the tensile strength is bigger than 600 MPa; the low temperature toughness meets the requirements of the minus 110 DEG C. The steel has high strength, excellent low temperature toughness, and can be suitable for manufacturing cryogenic vessel equipment in the field of petrifaction, liquefied gas storage, synthesis ammonia and the like.

Description

technical field [0001] The invention relates to a high-toughness pressure vessel steel, in particular to a -110°C low-temperature vessel steel and a manufacturing method thereof. Background technique [0002] With the rapid development of my country's petrochemical industry, the liquefaction and separation of gas and the production, storage, transportation and application of liquefied gas have become quite common. The rapid development of the national economy has promoted the market demand for steel for cryogenic pressure vessels. [0003] The -110°C grade low-temperature steel widely used at present is mainly 3.5Ni steel, and the production cost is relatively high. Prior to the present invention, the patent CN101235466A "a high-toughness -110°C low-temperature steel and its manufacturing method" adopts a relatively high Ni content (3.20-3.80%) and adds rare earth elements. The production process is complicated and the production cost is high. [0004] Patent CN101497961B "...

AI Technical Summary

Problems solved by technology

Prior to the present invention, the patent CN101235466A "a high-toughness -110°C low-temperature steel and its manufacturing method" adopts a relatively high Ni content (3.20-3.80%), and adds rare earth elements, the production process is complicated, and the production cost is high

[0004] Patent CN101497961B "a kind of low-temperature toughness 1.5Ni steel and its manufacturing method", adopts lower Ni content (1.20-1.60%), higher Mn content (1.00-1.50%), and uses controlled rolling and controlled cooling + quenching and tempering The steel plate produced by the process can meet the low temperature toughness requirement of -100°C, but the strength level of the patented steel plate is low, the tensile strength is only 500MPa, and its production process is relatively complicated (three-stage rolling process, low final cooling temperature at 300°C), it is not easy to control, and the production process cost is high

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