A method for smelting ultra-advanced duplex stainless steel made of cd3mwn

Abstract

A method for smelting ultra-advanced duplex stainless steel made of CD3MWN, which is designed for the internal control composition during smelting of duplex stainless steel; wherein C≤0.030 wt%, Si≤0.90 wt%, Mn is 1.20-2.50 wt%, P≤0.020 wt%, S≤0.015 wt%, Cr 26.2-27.5 wt%, Ni 6.2-7.6 wt%, Mo 2.2-3.4 wt%, Cu≤0.80 wt%, W≤0.80 wt%, N 0.32-0.38 wt%, B is 0.0010-0.0100 wt%, Ba is 0.0002-0.0100 wt%, Ce+La is 0.005-0.030 wt%; %Cr+3.3(%Mo+0.5%W)+16%N≥45, precise control of trace The content of elements B, Ba, Ce, and La; increase the N content to more than 0.30%, and at the same time avoid nitrogen pores in the casting; minimize the content of harmful elements such as sulfur, oxygen, hydrogen and other elements, and improve the liquid steel. purity. The poured casting has high strength and excellent corrosion resistance. The ratio of ferrite phase and austenite phase in stainless steel is close to 50%. The service life of the casting is prolonged, the manufacturing cost is greatly reduced, and the goals of energy saving, consumption reduction, and environmental protection are realized.

Description

technical field [0001] The invention belongs to the field of metal material metallurgy, and in particular relates to a process method for smelting super-advanced duplex stainless steel made of CD3MWN using an intermediate frequency induction furnace. Background technique [0002] Duplex stainless steel is stainless steel in which the ferrite phase and austenite phase each account for about half of the structure. Duplex stainless steel combines the excellent toughness of austenitic stainless steel with the higher strength and chloride stress corrosion resistance of ferritic stainless steel. The combination of properties makes duplex stainless steel have the advantages of both types of stainless steel materials, and it is widely used all over the world, mainly in oil and gas, chemical industry, marine engineering, shipbuilding, papermaking, food and light industry, and construction. [0003] However, for more demanding application environments, such as marine and deep-sea fiel...

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Problems solved by technology

[0010] At present, the intermediate frequency induction furnace melting process, intermediate frequency induction furnace + AOD furnace double melting process, electric arc furnace + AOD furnace double melting process, intermediate frequency induction furnace melting process, intermediate frequency Induction furnace + VOD furnace dual smelting process and electric arc furnace + VOD furnace dual smelting process, etc., using these smelting processes, duplex stainless steel that meets the composition requirements can be smelted, but the quality of molten steel is uneven and the composition fluctuates greatly. , Corrosion resistance is quite different, and the production cost is different

[0011] Intermediate frequency induction furnace + AOD furnace dual smelting process, electric arc furnace + AOD furnace dual smelting process, intermediate frequency induction furnace + VOD furnace dual smelting process and electric arc furnace + VOD furnace dual smelting process, the requirements for furnace materials are not very strict. Alloy charge can be used, such as returned furnace charge, scrap steel, ferromanganese, ferrochrome, electrolytic nickel, ferromolybdenum, etc., but the equipment investment is large, and it must be equipped with a refining furnace, which is suitable for large-scale production; dust, smoke and noise pollution, not environmentally friendly; induction furnace smelting is relatively environmentally friendly, and the production characteristics are highly adaptable, but the requirements for alloy furnace materials are higher

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