A smelting method for producing IF steel with low oxygen level in the whole process

A smelting method and a whole-process technology, applied in the field of iron and steel smelting, can solve the problems of unavoidable final slag oxidation of the converter, increase the labor load of on-site operators, and unfavorable on-site standardized operations, so as to improve the cleanliness level of molten steel and enhance decarburization effect, the effect of significant economic benefit

Active Publication Date: 2021-06-29
MAANSHAN IRON & STEEL CO LTD
View PDF1 Cites 0 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

At present, the smelting of IF steel is mainly produced by the technological process of "converter → alloy fine-tuning station → RH refining furnace → slab continuous casting". In the above-mentioned processes, on the one hand, the two operation sub-units of converter dephosphorization and RH decarburization require molten steel There is a certain amount of oxygen content, and the oxygen content at the end of the converter is too high, which will lead to strong oxidation of the final slag of the converter that inevitably enters the ladle, affecting the castability of molten steel in the continuous casting process; during the RH decarburization period, the oxygen content of molten steel is high, and the slag will be poured into the ladle. Transfer, thereby improving the oxidation of ladle slag, which is also not conducive to continuous casting; RH decarburization end point has high oxygen content, and the deoxidation product Al 2 o 3 The large amount of production will seriously affect the quality of IF steel. The Chinese patent "Smelting method of high-strength IF steel" has the following disadvantages: ① The oxygen content at the end of the converter is as high as 800-1000ppm. The oxygen content at the end point is still as high as 400-750ppm, such a high oxygen needs to be oxidized by adding aluminum, resulting in a large amount of deoxidized product Al 2 o 3 , which is not conducive to the quality of molten steel, and also increases the production cost; ②Adding slow-release deoxidizer multiple times, the amount of slow-release deoxidizer added needs to be adjusted according to specific smelting parameters, which increases the workload of on-site operators and is not conducive to on-site standardized operations. The Chinese patent "a method for composite deoxidation of ultra-low carbon IF steel" has the following disadvantages: ① The oxygen content is not controlled from the source

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • A smelting method for producing IF steel with low oxygen level in the whole process
  • A smelting method for producing IF steel with low oxygen level in the whole process
  • A smelting method for producing IF steel with low oxygen level in the whole process

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0027] from figure 1 It can be seen that the smelting method for producing IF steel in a whole process low-oxygen position of the present embodiment, the steps are:

[0028] Step 1: After the smelting of the converter steel, the slag is poured, and 10-15 tons of slag is left in the converter, and 50-100 kg of coke powder is added to remove the oxygen in the slag, and then the slag splashing operation is carried out to protect the furnace;

[0029] The chemical composition requirements of IF steel are: C≤0.0050%, Si≤0.01%, Mn: 0.08~0.25%, P≤0.015%, S≤0.008%, Als: 0.030~0.050%, Ti: 0.030~0.070%;

[0030] The slag composition range of converter slag is: TFe: 12-25%, CaO: 40-60%, SiO 2 : 10~18%, MnO: 2~3%, MgO: 3~6%;

[0031] Composition of coke powder is C≤94%, H2O≤0.020%, S≤0.022%, volatile + ash≤5%, particle size 5-15mm;

[0032] Step 2: Converter charging; the molten iron-scrap linkage ratio mode is adopted, and the amount of molten iron and scrap added is based on the prin...

Embodiment 2

[0064] A kind of smelting method of producing IF steel in the low oxygen position of the whole process of the present embodiment, its steps are:

[0065] Step 1: After the smelting of the last furnace of steel in the converter, the slag is dumped, leaving 13 tons of slag in the converter, adding 75 kg of coke powder to remove the oxygen in the slag, and then performing slag splashing to protect the furnace;

[0066] Step 2: Converter charging: adopt the molten iron-scrap linkage ratio mode, add 298t of molten iron and 33t of scrap steel, of which molten iron Si: 0.28%;

[0067] Step 3: Converter main blowing: Calculated according to “lime addition = 2.14×W[Si]×R×1000 / A”, the total lime addition is 27.1kg / t steel, where W[Si]: 0.28 %, R: 4, W(CaO): 90%, W(SiO 2): 0.35%: tapping amount: 297t, you need to add 8.0t of lime: 4 minutes before blowing: add lime to the converter in 3 batches, keep the lance position at 2.7m, and the oxygen flow rate of the top lance is 63000m 3 / h, ...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

PUM

No PUM Login to view more

Abstract

The invention discloses a smelting method for producing IF steel with low oxygen level in the whole process, and belongs to the technical field of iron and steel smelting. The steps of the present invention are as follows: step 1: slag dumping at the end of converter steel smelting, leaving 10-15 tons of slag in the converter, adding 50-100 kg of coke powder to remove oxygen in the slag, and then performing slag splashing to protect the furnace; step 2: charging the converter ;Step 3: Converter main blowing; Step 4: After the converter main blowing, measure the molten steel temperature and carbon content through the sub-lance, and control the auxiliary blowing oxygen amount according to the measured value; Step 5: After the auxiliary blowing, before tapping Bottom blowing for 30 seconds; Step 6: Converter tapping; Step 7: Molten steel enters the RH process; Step 8: After the ladle is lifted, turn on the vacuum pump to vacuum and decarburize. The invention can reduce the degree of peroxidation of molten steel in converter tapping, reduce the oxidizability of ladle top slag, and reduce deoxidized inclusions Al 2 o 3 The amount of production is increased, the cleanliness level of molten steel is improved, and the cost is reduced, which has significant economic benefits.

Description

technical field [0001] The invention relates to the technical field of iron and steel smelting, and more specifically, relates to a smelting method for producing IF steel with low oxygen level in the whole process. Background technique [0002] IF steel has excellent stamping and forming properties. At present, the smelting of IF steel is mainly produced by the technological process of "converter → alloy fine-tuning station → RH refining furnace → slab continuous casting". In the above-mentioned processes, on the one hand, the two operation sub-units of converter dephosphorization and RH decarburization require molten steel There is a certain amount of oxygen content, and the oxygen content at the end of the converter is too high, which will lead to strong oxidation of the final slag of the converter that inevitably enters the ladle, affecting the castability of molten steel in the continuous casting process; during the RH decarburization period, the oxygen content of molten...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

Application Information

Patent Timeline
no application Login to view more
Patent Type & Authority Patents(China)
IPC IPC(8): C21C5/35C21C5/36C21C7/10C21C7/06C21C7/068
CPCC21C5/35C21C5/36C21C7/0006C21C7/06C21C7/068C21C7/10Y02P10/20
Inventor 李应江李海波邓勇李宝庆单永刚胡晓光张雷谢大为熊华报张正群
Owner MAANSHAN IRON & STEEL CO LTD
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Try Eureka
PatSnap group products

Browse by: Latest US Patents, China's latest patents, Technical Efficacy Thesaurus, Application Domain, Technology Topic.

© 2024 PatSnap. All rights reserved.Legal|Privacy policy|Modern Slavery Act Transparency Statement|Sitemap