Method for smelting ultra-low-carbon steel by using single-nozzle refining furnace

A single nozzle refining furnace and ultra-low carbon steel technology, which is applied in the field of ultra-low carbon steel smelting, can solve the problems of short service life of dipping tube refractories, short molten steel treatment time, long molten steel treatment time, etc., and achieve short processing time, The effect of short smelting time and less serious erosion

Active Publication Date: 2010-08-04
北京北科三泰科技发展有限公司
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0005] The present invention mainly solves the technical problems existing in the prior art, such as the double-suction-nozzle type dipping tube, the small circulating flow rate of which causes long molten steel treatment time, serious nodulation of the dipping tube, and short service life of the dipping tube refractory material; it provides A method for smelting ultra-low carbon steel in a single-nozzle refining furnace with short molten steel treatment time, low refractory material consumption, and less nodulation in dipped tubes

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0023] Under the initial conditions of controlling the tapping slag thickness = 30mm, the molten steel temperature at 1570°C, and the carbon content at the station C = 0.051%, the following steps are performed:

[0024] Step 1: First slag the molten steel by blowing argon or nitrogen at the bottom. The flow of argon or nitrogen is 5.5Nl / min per ton of steel. When the exposed area of ​​molten steel reaches 50%, reduce the argon or nitrogen flow to 0.6Nl / min ton steel;

[0025] Step 2: Then insert the immersion tube of the single-nozzle furnace into the molten steel in step 1, and the depth of the immersion tube of the single-nozzle furnace into the molten steel is 400mm. At the same time adjust the position of the oxygen lance to 3300mm;

[0026] Step 3: Evacuate for 4 minutes to reach a vacuum of 78 Pa. During the evacuation process, blow argon at the bottom of the ladle at the same time. The argon flow rate is 4.7Nl / min / ton steel, and the argon flow rate remains unchanged until the...

Embodiment 2

[0028] Under the initial conditions of controlling the tapping slag thickness=50mm, the arrival molten steel temperature of 1615℃, and the arrival carbon content C=0.041%, the following steps are performed:

[0029] Step 1: First slag the molten steel by blowing argon or nitrogen at the bottom. The argon or nitrogen flow rate is 6Nl / min ton of steel. When the exposed area of ​​the molten steel reaches 40%, reduce the argon or nitrogen flow to 0.8 Nl / min ton steel;

[0030] Step 2: Then insert the immersion tube of the single-nozzle furnace into the molten steel in step 1, and the depth of the immersion tube of the single-nozzle furnace into the molten steel is 350mm. At the same time adjust the position of the oxygen lance to 2500mm;

[0031] Step 3: Vacuum for 5 minutes to reach a vacuum of 68pa. During the vacuuming process, argon is blown at the bottom of the ladle at the same time. The flow of argon is 5.8Nl / min / ton steel, and the flow of argon remains unchanged until the molten...

Embodiment 3

[0033] Under the initial conditions of controlling the tapping slag thickness=50mm, the arrival molten steel temperature of 1615℃, and the arrival carbon content C=0.07%, perform the following steps:

[0034] Step 1: First slag the molten steel by blowing argon or nitrogen at the bottom. The flow of argon or nitrogen is 7Nl / min per ton of steel. When the exposed area of ​​molten steel reaches 60%, reduce the argon or nitrogen flow to 0.7 Nl / min ton steel;

[0035] Step 2: Then insert the immersion tube of the single-nozzle furnace into the molten steel in step 1, and the depth of the immersion tube of the single-nozzle furnace into the molten steel is 350mm. At the same time adjust the position of the oxygen lance to 2500mm;

[0036] Step 3: Evacuate for 6 minutes to reach a vacuum of 68pa. During the evacuation process, blow argon at the bottom of the ladle at the same time. The argon flow rate is 3.7Nl / min / ton steel, and the argon flow rate remains unchanged until the molten steel...

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Abstract

The invention relates to a smelting method of ultra-low-carbon steel, which is an operating method for decarburizing by using a single-nozzle refining furnace. The invention is a smelting method for smelting ultra-low-carbon steel by using the single-nozzle refining furnace. The method is used for smelting the ultra-low-carbon steel with C of being less than or equal to 20ppm, and adjusts the inserting depth of a single-nozzle furnace dipping pipe, lance position of an oxygen lance, vacuum degree, oxygen supplying flow and eccentric bottom-blown argon of a steel ladle to stir molten steel under the vacuum condition by controlling the initial conditions of the thickness of a tapping slag layer, the temperature of arrived molten steel, the content of arrived carbon and the like so as to achieve the purpose of decarburization. The method has the following advantages that: 1. the treatment time of the molten steel is short, the refractory material consumption is low, and the scaffolding of the dipping pipe is little; and 2. the smelting time is short, the splashing is little, the consumption of sealing rings is less, the corrosion of the steel ladle is not serious, the cost is low and the operation is simple.

Description

Technical field [0001] The invention relates to a method for smelting ultra-low carbon steel, which is an operation method for decarburizing using a single nozzle refining furnace. Background technique [0002] The current large-scale production of ultra-low carbon steel is mainly RH and VOD smelting methods. [0003] ① RH (developed by Ruhrstahl and Heraeus by vacuum cycle degassing) adopts a double-nozzle dip tube, the molten steel in the ladle is inserted into the dip tube and then vacuumed, oxygen is supplied under vacuum and argon is blown from the side of the tube to smelt ultra-low carbon steel. Due to the use of the double-suction nozzle type dip tube in this method, the small circulating flow rate causes the problems of long treatment time of molten steel, serious nodulation of the dip tube, and short life of the dip tube. [0004] ②VOD (vacuum oxygen decarbruization of ladle in a vacuum tank) adopts a tank vacuum environment, top blowing oxygen, low argon or nitrogen blow...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C21C7/068C21C7/10
Inventor 郭汉杰张鉴成国光刘良田杨学民赵元庆刘志龙
Owner 北京北科三泰科技发展有限公司
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