Method for smelting low-sulfur steel by single-mouth refining furnace

A single nozzle refining furnace and low-sulfur steel technology, which is applied in the field of low-sulfur steel smelting, can solve the problems of long processing time, ineffective desulfurization effect, and failure to meet the requirements of special steel types, so as to avoid carbon and nitrogen increase Effect

Active Publication Date: 2011-04-13
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

[0003] ① The desulfurization effect of the converter in the steelmaking process is not obvious, and generally can reach the capacity of S ≤ 0.015%. To achieve the capacity of S ≤ 0.005% in molten steel, the refining furnace must be used for desulfurization, that is, RH and LF
However, when the LF electrode heats up, it will add carbon and nitrogen to the molten steel. For some steel types with high carbon and nitrogen requirements, desulfurization by this method cannot meet the requirements of special steel types.
The processing time is also too long, so that the time rhythm cannot be matched with the converter and continuous casting

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0022] A method for smelting low-sulfur steel, using a single nozzle refining furnace to desulfurize under the initial conditions of controlling the molten steel temperature at the arrival station at 1571°C and S=0.01%, and the specific steps are as follows:

[0023] Step 1. Firstly, the molten steel is deslagged by bottom blowing argon or nitrogen. The flow rate of argon or nitrogen is 5.5Nl / min per ton of steel. When the exposed area of ​​molten steel reaches 50%, the flow rate of argon or nitrogen is reduced to 0.6Nl / min ton of steel;

[0024] Step 2, insert the dipping tube of the single-nozzle furnace into the molten steel in step 1, and the depth of the dipping tube of the single-nozzle furnace inserted into the molten steel is 240mm;

[0025] Step 3, vacuumize to make the vacuum degree of the vacuum chamber reach 900pa;

[0026] Step 4, add deoxidizer, the deoxidizer is aluminum, the usage rate is 6kg / t, until the oxygen content in the molten steel is removed to 14ppm,...

Embodiment 2

[0028] A method for smelting low-sulfur steel, using a single nozzle refining furnace to desulfurize under the initial conditions of controlling the molten steel temperature at the arrival station at 1598°C and S=0.045%, and the specific steps are as follows:

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

[0030] Step 2, insert the dipping tube of the single-nozzle furnace into the molten steel in step 1, and the depth of the dipping tube of the single-nozzle furnace inserted into the molten steel is 240mm;

[0031] Step 3, vacuumize to make the vacuum degree of the vacuum chamber reach 480Pa;

[0032] Step 4, add deoxidizer, deoxidizer adopts aluminum alloy, use amount is 7kg / t (wherein use amount refers to pure aluminum content in aluminum a...

Embodiment 3

[0034] A method for smelting low-sulfur steel, using a single-nozzle refining furnace to desulfurize under the initial conditions of controlling the temperature of molten steel arriving at the station at 1656°C and S=0.051%, and the specific steps are as follows:

[0035] Step 1, firstly carry out slag removal to the molten steel by bottom blowing argon or nitrogen, the flow of argon or nitrogen is 7Nl / min ton of steel, when the exposed area of ​​molten steel reaches 60%, reduce the flow of argon or nitrogen to 0.7 Nl / min tons of steel;

[0036] Step 2, insert the dipping tube of the single-nozzle furnace into the molten steel in step 1, and the depth of the dipping tube of the single-nozzle furnace inserted into the molten steel is 400mm;

[0037] Step 3, vacuumize the vacuum chamber so that the vacuum degree reaches 220Pa;

[0038] Step 4, add deoxidizer, aluminum is used as deoxidizer, the usage amount is 5kg / t, until the oxygen content in molten steel is depleted to 5ppm,...

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PUM

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Abstract

The invention relates to a method for smelting low-sulfur steel, which adopts the operation method of using a single-mouth refining furnace for desulfuration. The invention provides the method for smelting the low-sulfur steel by the single-mouth refining furnace. The method can be used for smelting the low-sulfur steel with S less than or equal to 0.005%; the temperature of molten steel is 1560-1680 DEG C, and the initial S is less than or equal to 0.01%; deoxidizing agent is added under the vacuum condition, and desulfurizing agent is then added until the oxygen content inside the molten steel reaches 4-15ppm; and argon or nitrogen is blown at the bottom, and stirring the molten steel for desulfuration within 25min. Therefore, the method has the advantages that 1. the desulfurization rate reaches more than 70%; and 2. carbon and nitrogen inside the molten steel can be avoided being increased in the smelting process.

Description

technical field [0001] The invention relates to a low-sulfur steel smelting method, which is a desulfurization operation method using a single nozzle refining furnace. Background technique [0002] At present, the methods of large-scale production of low-sulfur steel are mainly smelting methods using converters, RH and LF. [0003] ① The desulfurization effect of the converter in the steelmaking process is not obvious, and generally can reach the capacity of S ≤ 0.015%. To achieve the capacity of S ≤ 0.005% in molten steel, the refining furnace must be used for desulfurization, that is, RH and LF. [0004] ②RH (developed by Ruhrstahl and Heraeus by vacuum circulation degassing method) adopts double-mouth dipping tube for desulfurization. Because the steel slag interface is small, it is not conducive to desulfurization, and its desulfurization rate can only reach below 30%. [0005] ③ LF (Ladle Furnace) adopts electrode heating to desulfurize by adding desulfurizer under th...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C21C7/064
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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