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Chromium-containing low-nickel molten iron pretreatment process and application for 200-series stainless steel production

A stainless steel, nickel molten iron technology, applied in the direction of manufacturing converters, etc., can solve the problems of increasing equipment cost, affecting production efficiency, intensifying erosion, etc., to avoid oxidation, increase decarburization efficiency, and improve the effect of mixing degree

Active Publication Date: 2020-02-21
BAOSTEEL DESHENG STAINLESS STEEL
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, its biggest defect is: due to the bottom blowing of oxygen, nitrogen and argon mixed gas in the GOR primary smelting furnace, oxygen enters the molten pool through bottom blowing, so that the heat generated by the reaction of oxygen and C is concentrated near the furnace bottom refractory, resulting in erosion Intensified, from a practical point of view: the age of the GOR furnace as the primary smelting furnace is generally between 250-350 furnaces. The furnace age is low, which increases the cost of equipment. At the same time, the replacement of the primary smelting furnace also affects the production efficiency

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0027] A kind of chromium-containing low-nickel molten iron pretreatment process for the production of 200 series stainless steel comprises the following steps:

[0028] temperature C Si mn Cr Ni P S 1310℃ 4.6％ 1.15％ 1.26％ 4.5％ 1.47％ 0.036％ 0.060％

[0029] (2) When the carbon in the molten pool in the primary smelting furnace is reduced to 1.50%, the silicon is reduced to 0.10%, and the end point temperature is controlled at 1680°C, the top lance of the primary smelting furnace stops blowing oxygen, and then it is added to the primary smelting furnace High-carbon ferrochrome, the main chemical composition mass percentage of high-carbon ferrochrome is: C: 5-6.8%; Si: 3-4.0%; Cr: 50-60%; The inputs of carbon chrome molten iron and solid high-carbon ferrochrome are: 85 tons, 5 tons, and 10 tons;

[0030] (3) Then blow nitrogen or inert gas into the molten pool through the bottom lance of the primary furnace, and the blowing intensity is controll...

Embodiment 2

[0036] Embodiment 2 is different from embodiment 1 in that:

[0037] temperature C Si mn Cr Ni P S 1300℃ 4.3% 0.90% 1.25% 4.6% 1.45% 0.037% 0.066%

[0038] b. When the carbon in the molten pool in the primary smelting furnace is reduced to 1.00% and the end point temperature is controlled at 1650°C, the top lance of the primary smelting furnace stops blowing oxygen;

[0039] c, the inputs of chromium-containing low-nickel molten iron, molten high-carbon ferrochrome, and solid-state high-carbon ferrochrome are respectively: 83 tons, 11 tons, and 6 tons;

[0040] d. The tapping temperature is controlled at 1530°C, and the slag basicity is controlled at 1.45.

[0041] C Si mn P Cr Ni 2.0 0.13 0.51 0.046 13.59 1.39

[0042] Cr in slag 2 o 3 The content is 0.61%.

[0043] C Si mn P Cr Ni 0.114 0.60 9.8 0.042 13.44 1.38

Embodiment 3

[0045] Embodiment 3 is different from embodiment 1 in that:

[0046] temperature C Si mn Cr Ni P S 1310℃ 4.8% 1.10% 1.26% 4.5% 1.48% 0.036% 0.060%

[0047] b. When the carbon in the molten pool in the primary smelting furnace is reduced to 0.6% and the end point temperature is controlled at 1620°C, the top lance of the primary smelting furnace stops blowing oxygen;

[0048] c, the inputs of chromium-containing low-nickel molten iron, molten high-carbon ferrochrome, and solid-state high-carbon ferrochrome are respectively: 80 tons, 10 tons, and 5 tons;

[0049] d. The tapping temperature is controlled at 1480°C, and the slag basicity is controlled at 1.3.

[0050] C Si mn P Cr Ni 3.50 0.20 0.9 0.048 13.56 1.38

[0051] Cr in slag 2 o 3 The content is 0.63%.

[0052] C Si mn P Cr Ni 0.075 0.43 10.76 0.041 13.41 1.27

[0053] Therefore, the Cr content in the rough smelting hot meta...

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Abstract

The invention aims at providing a chromium-containing low-nickel molten iron pretreatment process and application for 200-series stainless steel production. The process comprises the following steps that chromium-containing low-nickel molten iron is added into a top-bottom compound blowing primary smelting furnace, and blowing smelting is conducted in the primary smelting furnace under the conditions of top lance oxygen blowing and bottom lance no oxygen blowing; when the carbon in a melting pool in the primary smelting furnace is reduced to 0.60%-1.50%, the silicon is reduced to less than 0.10%, and the endpoint temperature is controlled to range from 1620 DEG C to 1680 DEG C, oxygen blowing of a top lance of the primary smelting furnace is stopped, and then solid high-carbon ferrochromeand molten high-carbon ferrochrome are added into the primary smelting furnace; and a bottom lance of the primary smelting furnace is used for blowing nitrogen or inert gas into the melting pool, theblowing intensity of the bottom lance is controlled to range from 0.18 Nm<3> / t.min to 0.30 Nm<3> / t.min for stirring, slag is blocked for steel discharging, and then coarse smelting molten iron for 200-series stainless steel production is obtained, wherein the slag basicity is controlled to range from 1.3 to 1.6. According to the chromium-containing low-nickel molten iron pretreatment process, thewear resistance of furnace-bottom refractory materials of the primary smelting furnace can be reduced, the furnace age of the primary smelting furnace is proloned, and the equipment cost is reduced.

Description

technical field [0001] The invention belongs to the field of stainless steel manufacturing technology, in particular to a pretreatment process and application of chromium-containing low-nickel molten iron used in the production of 200 series stainless steel. Background technique [0002] The existing technologies for producing 200 series stainless steel mainly include the following types: [0003] 1) Electric furnace + AOD furnace smelting stainless steel method: This technology uses electric furnace to melt scrap steel and alloys to produce stainless steel rough smelting molten steel, and then blends it into AOD furnace for refining to produce stainless steel; [0004] 2) Electric furnace + VOD stainless steel smelting method: This method uses electric furnace to melt scrap steel and alloys to produce stainless steel, and then mixes it with VOD to produce stainless steel after rough smelting; [0005] 3) AOD furnace (or GOR furnace) direct smelting method: the dephosphoriz...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C22C33/04C22C37/08C22C37/10C21C1/00C21C5/35C21C7/072
CPCC21C1/00C21C5/005C21C7/072C22C33/04C22C37/08C22C37/10
Inventor 陈为本邵世杰黎涛黎开文王志勇
Owner BAOSTEEL DESHENG STAINLESS STEEL
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