Method for producing duplex stainless steel

Abstract

The invention discloses a method for producing duplex stainless steel. The method comprises the steps that 1, molten iron is desiliconized and dephosphorized, alloy is molten in an intermediate frequency furnace, the treated molten iron and the molten alloy are mixed into a refining furnace for decarbonization, reduction, nitrogen discharging and deep desulfurization, and after the mass fraction of components of molten steel meets the preset requirement, the molten steel is tapped to a steel ladle; 2, the refining furnace is pulled in, argon blowing is carried out after the refining furnace is pulled in, after electrochemical residues are fed, a pure calcium line is added, lime and fluorite are added, power is transmitted to heat the molten steel, aluminum particles are added according to the residue color condition to adjust the residue color to be white, and after the mass fraction of the molten steel meets the preset requirement, argon flow is adjusted, ferroboron is added, and steel tapping is carried out soft blowing; 3, after the molten steel stands still, pouring is carried out, and duplex stainless steel blanks are produced.

Description

technical field

[0001] The invention belongs to the technical field of stainless steel smelting, and in particular relates to a production method of duplex stainless steel. Background technique

[0002] At present, in duplex stainless steel, the ferrite phase and austenite phase account for about half of the solid solution structure, and the content of the general minor phase also needs to reach 30%. In the case of low C content, the Cr content is 18% to 28%, and the Ni content is 3% to 10%. Some steels also contain alloying elements such as Mo, Cu, Nb, Ti, and N. This type of steel has the characteristics of both austenitic and ferritic stainless steel, and has good mechanical and corrosion resistance properties. It is widely used in the fields of ships, petroleum, chemical industry, papermaking and so on. At present, most of the production of duplex stainless steel adopts the production mode of electric furnace + AOD (such as Chinese patent applications CN201110126703, C...