Method for producing duplex stainless steel

A duplex stainless steel and production method technology, applied in the field of stainless steel smelting, can solve the problems of high smelting cost, low alloy yield, high raw material requirements, etc., and achieve low smelting cost, increase alloy yield, and improve product quality Effect

Inactive Publication Date: 2015-12-23
SHANDONG TAISHAN STEEL GROUP
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

At present, most of the production of duplex stainless steel adopts the production mode of electric furnace + AOD (such as Chinese patent applications CN201110126703, CN201110306023, CN201210170317 and CN201310001748). Due to the use of electric furnaces to smelt semi-steel, the requirements for raw materials are high, the yield of alloys is low, and even the subsequent increase in VOD vacuum Refining process, higher smelting cost

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0020] A steel company implements the patent of this invention to produce 20 heats of duplex stainless steel with the grade of 022Cr23Ni5Mo3N. The mass fraction of molten steel is controlled as follows: C: ≤0.025%, Si: 0.35-0.55%, Mn: 1.10-1.4%, P: ≤0.030%, S: ≤0.002%, Cr: 22.3-22.6%, Ni: 5.05-5.15%, Mo: 3.0-3.5%, N: 0.14-0.18%, and the rest are Fe and unavoidable impurities. The process flow is:

[0021] 1. Desiliconization and dephosphorization of molten iron

[0022] The desiliconization and dephosphorization of molten iron is carried out in the molten iron tank, using the blowing method to dephosphorize, and the top blowing oxygen flow rate is 26Nm 3 / min, the gun position is 0.8m, the flow rate of lime powder sprayed by the dusting gun is 40kg / min, the distance between the gun position and the bottom of the tank is less than 500mm, the iron scale is 0.20kg per ton of molten iron, blowing is started for 25 minutes, slag is removed and sampled, Si≤0.15%, Entering the deph...

Embodiment 2

[0036] A steel company implements the patent of this invention to produce 15 furnaces of duplex stainless steel with the grade of 022Cr23Ni5Mo3N. The mass fraction of molten steel is controlled as follows: C: ≤0.025%, Si: 0.35-0.55%, Mn: 1.10-1.4%, P: ≤0.030%, S: ≤0.002%, Cr: 22.3-22.6%, Ni: 5.05-5.15%, Mo: 3.0-3.5%, N: 0.14-0.18%, and the rest are Fe and unavoidable impurities. The process flow is:

[0037] 1. Desiliconization and dephosphorization of molten iron

[0038] The desiliconization and dephosphorization of molten iron is carried out in the molten iron tank, using the blowing method to dephosphorize, and the top blowing oxygen flow rate is 10Nm 3 / min, the gun position is 0.7m, the flow rate of lime powder sprayed by the dusting gun is 20kg / min, the distance between the gun position and the bottom of the tank is less than 500mm, the iron scale is 0.10kg per ton of molten iron, blowing is started for 20 minutes, slag is removed and sampled, Si≤0.15%, Entering the d...

Embodiment 3

[0052] A steel company implements the patent of this invention to produce 18 furnaces of duplex stainless steel with the grade of 022Cr23Ni5Mo3N. The mass fraction of molten steel is controlled as follows: C: ≤0.025%, Si: 0.35-0.55%, Mn: 1.10-1.4%, P: ≤0.030%, S: ≤0.002%, Cr: 22.3-22.6%, Ni: 5.05-5.15%, Mo: 3.0-3.5%, N: 0.14-0.18%, and the rest are Fe and unavoidable impurities. The process flow is:

[0053] 1. Desiliconization and dephosphorization of molten iron

[0054] The desiliconization and dephosphorization of molten iron is carried out in the molten iron tank, using the blowing method to dephosphorize, and the oxygen flow rate of top blowing is 30Nm 3 / min, the gun position is 1.0m, the flow rate of lime powder sprayed by the dusting gun is 50kg / min, the distance between the gun position and the bottom of the tank is less than 500mm, the iron oxide scale is 0.20kg per ton of molten iron, blowing is started for 30 minutes, slag is removed and sampled, Si≤0.15%, Enter...

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PUM

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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...

Claims

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Application Information

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IPC IPC(8): C22C33/04
Inventor 王永胜陈茂宝赵刚徐光富魏述一亓传军殷齐敏焦玉水吴荣刚颜凯许桂兴
Owner SHANDONG TAISHAN STEEL GROUP
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