Looking for breakthrough ideas for innovation challenges? Try Patsnap Eureka!

Production method for low-residual-chromium-content molten steel and steel material

A technology of chromium content and molten steel, which is applied in the direction of manufacturing converters, etc., can solve the problems such as the reduction of process indicators of molten iron pretreatment, the reduction of dephosphorization efficiency, and the deterioration of efficiency, so as to be suitable for large-scale industrial production applications, with reasonable process conditions, The effect of broad adaptability

Active Publication Date: 2018-01-23
攀钢集团西昌钢钒有限公司
View PDF4 Cites 5 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0004] However, as the chromium-containing iron ore blast furnace smelting process is overcome and gradually matured, the chromium content in molten iron smelted in the blast furnace will inevitably increase, and the increase in molten iron chromium will lead to a decrease in the technical indicators of molten iron pretreatment, especially the use of vanadium extraction and molten iron pretreatment. Manufacturers of dephosphorization and desulfurization processes
Firstly, in the molten iron pretreatment process, with the increase of the Cr content in the molten iron, the hardness of the slag will be increased, the condition of the slag will be deteriorated, the efficiency of desulfurization and vanadium extraction will be deteriorated, and problems such as tank bonding will be prominent. Chromium oxides will increase the hardness of slag, reduce the dephosphorization efficiency, and cause P to exceed the standard; it will also cause excessive residual elements in converter smelting, which will have an adverse effect on steel grades. However, high cleanliness steel grades (American standard heavy rail, High-grade electrical steel, cord steel) usually require the lower the residual elements, the better
However, under normal circumstances, the residual Cr element in molten steel usually increases to more than 100ppm to 200ppm, which has a serious impact on the performance and stability of the steel.

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

Examples

Experimental program
Comparison scheme
Effect test

preparation example Construction

[0040] The invention provides a method for preparing molten steel with low chromium content, comprising the following steps:

[0041] 1) Send the molten iron into the converter for the first converter smelting, adding coolant and recarburizer during the smelting process to obtain low-chromium semi-steel;

[0042] 2) Send the dechromed semi-steel obtained in the above steps into the converter again for the second converter smelting, adding a dephosphorizing agent during the smelting process to obtain molten steel with low chromium content.

[0043] In the invention, the molten iron is first sent into the converter for the first converter smelting, and a coolant and a recarburizer are added during the smelting process to obtain low-chromium semi-steel.

[0044] The sources and parameters of the molten iron described in the present invention are not particularly limited, and the sources and parameters of the molten iron well known to those skilled in the art can be used. Those sk...

Embodiment 1

[0082] Pangang Group Xichang Steel and Vanadium Co., Ltd. produces low-chromium steel M4R18 automotive steel.

[0083] For M4R18 steel production furnaces, the chromium content of molten iron is 0.058. After the first converter (i.e., vanadium extraction converter) is mixed with iron, the molten iron is placed at an oxygen supply intensity of 1.5Nm 3 / t.min~2.5Nm 3 Blowing is carried out under the condition of / t.min. During the smelting process, (cold briquette) coolant and (anthracite) recarburizer are added to the furnace. The amount of coolant is 10-100kg / t steel, and the amount of recarburizer is between 1-10kg / t steel; the position of the oxygen lance is controlled between 1.4-2.5 meters, the content of FeO in the slag is controlled between 25-40%, to ensure that the slag has sufficient oxidation, and the tapping temperature of the converter is controlled at ≤1280°C, low chromium semi-steel is obtained. The slag-stopping equipment is used for tapping the converter to c...

Embodiment 2

[0087] For 50PW600 electrical steel production furnaces, the chromium content of molten iron is 0.048. After the first converter (i.e., the vanadium extraction converter) is finished adding iron, the molten iron is placed at an oxygen supply intensity of 1.5Nm 3 / t.min~2.5Nm 3 Blowing under the condition of / t.min, add 20kg / t steel of cold briquetting into the furnace after 1min of smelting, and 2kg / t steel of anthracite recarburizer; continue to add 20kg of cold briquetting into the furnace after blowing for 3min / t steel, anthracite recarburizer 2kg / t steel coolant and (anthracite) recarburizer; after blowing for 6 minutes, continue to add cold briquette 10kg / t steel, anthracite recarburizer 1kg / t into the furnace, blowing Lift the gun to pour out the vanadium slag at 7 minutes. The amount of coolant is 10-100kg / t steel, the amount of carburizer is 1-10kg / t steel; the gun position of the oxygen lance is controlled between 1.4-2.5 meters, and the content of FeO in the slag i...

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 provides a preparing method for low-chromium-content molten steel. The preparing method includes the following steps that firstly, molten iron is sent into a converter for the first timeof converter smelting, a cooling agent and a carburant are added in the smelting process, and low-chromium half steel is obtained; and the chromium-removed half steel obtained in the above step is sent into a converter again for the second time of converter smelting, a dephosphorizing agent is added in the smelting process, and low-chromium-content molten steel is obtained. By means of the preparing method, a duplex chromium removing technology is used for removing chromium in the molten iron, the cooling agent is added in the first converter for controlling the converter temperature, the carburant is added for supplementing carbon losses in the chromium removing process, chromium in the molten iron is removed to the maximum degree, and efficient removing of chromium is achieved; and thesecond converter is used for conducting the second time of deep chromium removing, and meanwhile conventional steelmaking tasks such as decarbonizing and dephosphorizing are completed. By means of thepreparing method, the residual Cr content of the molten steel can be controlled to be within 40 ppm, and a foundation is laid for production of high-purity steel balls. In addition, the technology issimple, extra production equipment does not need to be added, conditions are reasonable, and the method is suitable for large-scale industrial production.

Description

technical field [0001] The invention belongs to the technical field of iron and steel smelting, and relates to a production method and steel material of molten steel with low chromium content, in particular to a production method and steel material of molten steel with low residual chromium content. Background technique [0002] Converter steelmaking (converter steelmaking) uses molten iron, scrap steel, and ferroalloy as the main raw materials, and completes the steelmaking process in the converter by relying on the physical heat of the molten iron itself and the chemical reaction between the components of the molten iron to generate heat without resorting to external energy. According to the refractory material, the converter is divided into acidic and alkaline; according to the position where the gas is blown into the furnace, there are top blowing, bottom blowing and side blowing; according to the type of gas, it is divided into air converter and oxygen converter. Basic ...

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
IPC IPC(8): C21C5/28C21C7/00C21C7/06
Inventor 张彦恒龚洪君喻林
Owner 攀钢集团西昌钢钒有限公司
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Patsnap Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Patsnap Eureka Blog
Learn More
PatSnap group products

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

© 2024 PatSnap. All rights reserved.Legal|Privacy policy|Modern Slavery Act Transparency Statement|Sitemap|About US| Contact US: help@patsnap.com