Method for smelting austenitic stainless steel by blowing carbon dioxide in AOD converter

A technology of austenitic stainless steel and converter, which is applied in the manufacture of converters, etc. It can solve the problems of high steelmaking cost and low utilization rate of carbon dioxide resources, so as to avoid the pollution of molten steel, reduce the absolute amount, and increase the yield of iron element rate effect

Inactive Publication Date: 2020-10-30
GANSU JIU STEEL GRP HONGXING IRON & STEEL CO LTD
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  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0004] The object of the present invention is to provide a kind of AOD converter injection CO 2 The method for smelting austenitic stainless steel solves the problems of low resource utilization rate of carbon dioxide and high steelmaking cost in the existing iron and steel smelting process

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0023] Smelting steel type: 304 austenitic stainless steel, the smelting steps are as follows:

[0024] a. Add molten iron: inject 90t molten iron with a melting temperature of 1450°C into the AOD converter. The chemical composition of the molten iron is C 2.00%, Si 0.40%, Mn 0.10%, P 0.043%, S 0.10 in terms of mass percentage %, Cr 9.0%, Ni 8.00%, the rest is Fe and unavoidable impurities;

[0025] b. Decarburization: lime is added in the decarburization stage, and the total amount of lime added is 10kg / t steel;

[0026] ①Silicon-aluminum oxidation period: the oxygen flow rate of the top gun is 100Nm 3 / min, side gun oxygen flow rate 100Nm 3 / min, nitrogen flow 30Nm 3 / min, the blowing time is 2min, the amount of light-burned dolomite added is 2kg / t of steel, and 180kg of light-burned dolomite is added;

[0027] ②Main decarburization period: top gun oxygen flow rate 100Nm 3 / min, side gun oxygen flow rate 100Nm 3 / min, nitrogen flow 30Nm 3 / min, blowing time is 2min; ...

Embodiment 2

[0036] Smelting steel type: 304 austenitic stainless steel, the smelting steps are as follows:

[0037] a. Add molten iron: inject 95t molten iron with a melting temperature of 1500°C into the AOD converter. The chemical composition of the molten iron is C 2.50%, Si 0.70%, Mn 0.20%, P 0.040%, S 0.08 in terms of mass percentage %, Cr 8.0%, Ni 8.30%, the rest is Fe and unavoidable impurities;

[0038] b. Decarburization: Lime is added in the decarburization stage, and the total amount of lime added is 12kg / t steel;

[0039] ①Silicon-aluminum oxidation period: the oxygen flow rate of the top gun is 120Nm 3 / min, side gun oxygen flow rate 110Nm 3 / min, nitrogen flow 40Nm 3 / min, the blowing time is 3min, the amount of light-burned dolomite added is 3kg / t steel, and 285kg of light-burned dolomite is added;

[0040] ②Main decarburization period: top gun oxygen flow rate 120Nm 3 / min, side gun oxygen flow rate 110Nm 3 / min, nitrogen flow 40Nm 3 / min, blowing time is 3min;

[...

Embodiment 3

[0049] Smelting steel type: 304 austenitic stainless steel, the smelting steps are as follows:

[0050] a. Add molten iron: inject 92t molten iron with a melting temperature of 1460°C into the AOD converter. The chemical composition of the molten iron is C 2.2%, Si 0.50%, Mn 0.15%, P 0.035%, S 0.09 in terms of mass percentage %, Cr 8.50%, Ni 8.1%, the rest is Fe and unavoidable impurities;

[0051] b. Decarburization: lime is added in the decarburization stage, and the total amount of lime added is 11kg / t steel;

[0052] ①Silicon-aluminum oxidation period: top gun oxygen flow rate 110Nm 3 / min, side gun oxygen flow rate 105Nm 3 / min, nitrogen flow 35Nm 3 / min, the blowing time is 3.5min, the amount of light-burned dolomite added is 2.4kg / t of steel, and 220.8kg of light-burned dolomite is added;

[0053] ②Main decarburization period: top gun oxygen flow rate 110Nm 3 / min, side gun oxygen flow rate 105Nm 3 / min, nitrogen flow 35Nm 3 / min, blowing time is 2.5min;

[0054...

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Abstract

The invention provides a method for smelting austenitic stainless steel by blowing CO2 in an AOD converter. The method comprises the following steps of adding molten iron, decarburizing, reducing anddesulfurizing, wherein desulfurizing comprises seven stages, and CO2 is blown by an inner gun blower gun from a dynamic decarburization period 2 to a dynamic decarburization period 5 to replace 50% ofN2. According to the method, based on the initial smelting condition, CO2 and O2 with different contents are mixed and blown in different decarburization stages, so that the requirements of the converter on the silicon content and the temperature of the pre-molten iron are reduced, thus large slag amount and molten steel pollution caused by excessive addition of calcined dolomite and lime can beavoided, the resource utilization of carbon dioxide is realized to a certain extent, and the steel smelting cost is reduced.

Description

technical field [0001] The invention belongs to the technical field of stainless steel smelting, and relates to an AOD converter injecting CO 2 A method of smelting austenitic stainless steel. Background technique [0002] There is CO in the stainless steel smelting process 2 Large emissions, high energy consumption, and high cost. Therefore, in order to remain invincible in the increasingly fierce steel market competition, Chinese iron and steel enterprises must master low-cost production technology as soon as possible to achieve energy saving, emission reduction, high efficiency and economy. With the capacity and scale of production, under this background, breaking through the traditional smelting process, developing new processes and saving energy and reducing consumption have become more and more concerns of stainless steel manufacturers. [0003] Carbon dioxide occupies a large proportion of metallurgical gas emissions. How to reduce carbon dioxide emissions and make ...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C21C7/064C21C7/068C21C7/072C21C5/30
CPCC21C5/005C21C7/064C21C7/0685C21C7/072
Inventor 陈兴润潘吉祥李振刚吴德明
Owner GANSU JIU STEEL GRP HONGXING IRON & STEEL CO LTD
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