AOD smelting technique for stainless steel

A technology of stainless steel and process, applied in the field of AOD smelting process of stainless steel, can solve the problems of unstable smelting cycle, decrease in the number of continuous pouring furnaces, and decrease in furnace age, so as to avoid equipment selection errors, reduce smelting costs, and increase continuous pouring The effect of furnace number

Active Publication Date: 2017-01-11
XINGTAI IRON & STEEL
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0003] Due to the theoretical inconsistency in the above three points of the steel mills, there is no clear concept, resulting in great differences in operation, mainly in: (1) The instability of the smelting cycle: the same raw material, the same steel type , due to the difference in concept, or the lack of a clear idea of ​​operation, the smelting cycle is very different, ranging from a dozen points to a few tens of points
Moreover, the cycle stability is very poor, causing huge waste to production organization and cost
[0004] (2) Frequent production accidents: oxygen lance sticking to steel, steel slag splashing
Oxygen lance sticking to steel brings great hidden dangers to safe production; steel slag splashes cause early damage to fume hoods and flues, and deteriorates the operating environment for workers
[0005] (3) Increase in smelting cost: the extension of the smelting cycle leads to an increase in heat loss, a decrease in furnace age, and a decrease in the number of continuous pouring furnaces; resulting in an increase in the consumption of refractory materials, alloy ferrosilicon, and slag lime and fluorite. High, lower recovery rate of molten steel, higher continuous casting operating costs, etc., so that the product competitiveness is reduced

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0019] Embodiment 1: Taking chrome-nickel 300 series 304 as an example, the specific steps of the AOD smelting process of this stainless steel are as follows.

[0020] (1) The composition content of each raw material:

[0021] Mother liquor composition (wt): C 2.0%, Si 0.25%, Mn 0.50%, Cr 10.00%, Ni 6.00%, the balance is Fe and unavoidable impurities; mother liquor temperature 1500°C.

[0022] Return scrap composition (wt): C 0.05%, Si 0.40%, Mn 1.00%, Cr 18.00%, Ni 8.00%, the balance is Fe and unavoidable impurities; return scrap weight 4000 kg; return scrap temperature 20°C.

[0023] Ferrochromium composition (wt): C 6.99%, Si 3.11%, Mn 0.00%, Cr 52.04%, Ni 0.17%, the balance is Fe and unavoidable impurities.

[0024] (2) Calculate the material balance and heat balance according to the following objectives: the main blowing end temperature is controlled at 1690°C, the slag basicity is 3.5; the chromium oxide content in the slag is 15wt%; the slag amount is 70 kg / ton of stee...

Embodiment 2

[0028] Example 2: Taking the chromium series 0Cr13C as an example, the specific steps of the AOD smelting process of this stainless steel are as follows.

[0029] (1) The composition content of each raw material:

[0030] Mother liquor composition (wt): C 3.50%, Si 0.01%, Mn 0.15%, Cr 0.03%, Ni 0.02%, the balance is Fe and unavoidable impurities; mother liquor temperature 1300°C.

[0031] Return scrap composition (wt): C 0.05%, Si 0.40%, Mn 0.2%, Cr 12.00%, Ni 0.00%, the balance is Fe and unavoidable impurities; return scrap temperature 20°C.

[0032] Ferrochrome composition (wt): C 6.53%, Si 3.50%, Mn 0.00%, Cr 52.94%, Ni 0.22%, the balance is Fe and unavoidable impurities.

[0033] Ordinary ferrochromium composition (wt): C 7.32%, Si 3.21%, Mn 0.00%, Cr 50.98%, Ni 0.18%, the balance is Fe and unavoidable impurities.

[0034] (2) Calculate the material balance and heat balance according to the following objectives: the main blowing end temperature is controlled at 1680°C, t...

Embodiment 3

[0038] Embodiment 3: Taking the chromium series 0Cr13C as an example, the specific steps of the AOD smelting process of this stainless steel are as follows.

[0039] (1) The composition content of each raw material:

[0040] Mother liquor composition (wt): C 3.50%, Si 0.01%, Mn 0.15%, Cr 0.03%, Ni 0.02%, the balance is Fe and unavoidable impurities; mother liquor temperature 1300°C.

[0041]Return scrap composition (wt): C 0.05%, Si 0.40%, Mn 0.2%, Cr 12.00%, Ni 0.00%, the balance is Fe and unavoidable impurities; return scrap temperature 20°C.

[0042] Ferrochrome composition (wt): C 6.66%, Si 4.05%, Mn 0.00%, Cr 49.08%, Ni 0.23%, the balance is Fe and unavoidable impurities.

[0043] Ordinary ferrochromium composition (wt): C 7.32%, Si 2.72%, Mn 0.00%, Cr 48.79%, Ni 0.17%, the balance is Fe and unavoidable impurities.

[0044] (2) Calculate the material balance and heat balance according to the following objectives: the main blowing end temperature is controlled at 1700°C,...

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PUM

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Abstract

The invention discloses an AOD smelting technique for stainless steel. The AOD smelting technique comprises the technological steps that material balance and heat balance are calculated according to steel element requirements and chemical heating parameters of all elements, and the adding quantities of raw materials are determined; and target requirements are calculated, specifically, the basicity of slag formed after a main blowing decarburization stage is ended is 3.0-4.0, and the main blowing ending temperature is controlled to 1680-1700 DEG C. According to the AOD smelting technique for the stainless steel, the smelting cost can be reduced, and the production order can be stabilized; the smelting cycle can be obviously shortened, material consumption is reduced, and the number of continuous casting is increased; and a steelmaking plant is assisted in reasonably selecting equipment investment through calculation of the material balance and heat balance according to the raw material condition, and equipment type selection mistakes are avoided.

Description

technical field [0001] The invention relates to a method for smelting stainless steel, in particular to an AOD smelting process for stainless steel. Background technique [0002] At present, my country's iron and steel industry is in the stage of structural adjustment, the proportion of special steel is gradually increasing, and stainless steel and heat-resistant steel occupy the vast majority of the special steel field, and the quality of its development directly restricts the survival of enterprises. As the mainstream equipment for smelting stainless steel and heat-resistant steel, AOD accounts for more than 80% of the total amount of stainless steel and heat-resistant steel. However, there is a big difference in concept during the AOD operation process, and the most prominent ones are the following points: (1) The time and speed of adding cold material; (2) The control of chromium oxidation during the main blowing period; (3) Control of slag basicity during dynamic decar...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C21C7/068C22C33/04
CPCC21C5/005C21C7/0685C22C33/04
Inventor 吴广海王郢曹洪波叶凡新胡黎宁王秋坤冯文甫郭志彬白李国
Owner XINGTAI IRON & STEEL
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