Method for controlling nitrogen increasing of converter tapping molten steel

A converter and molten steel technology, applied in the manufacture of converters, etc., can solve the problems of no effective control methods, affecting the quality and performance of steel, and achieve the effect of reducing nitrogen content, meeting the needs of performance, and improving the quality of finished steel

Inactive Publication Date: 2012-05-09
ANGANG STEEL CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, most of its research focuses on the refining furnace, and there are few studies on the nitrogen increase of molten steel during the tapping process of the converter, especially for the killed steel. There is no effective control method for nitrogen increase at this stage, which directly affects the quality and performance of steel

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0012] 1. Control the oxygen content of tapping: After actual measurement, when the carbon weight of tapping is 0.08%, the oxygen content of tapping is controlled at 4800ppm.

[0013] 2. Control the adding sequence of deoxidized alloy: use alloy material tank to add alloy, and change the adding sequence of deoxidized alloy after converter from strong deoxidized alloy, weakly deoxidized alloy, non-deoxidized alloy to non-deoxidized alloy, weakly deoxidized alloy, strong deoxidized alloy , that is, first add non-deoxidizing alloy to the bottom of the tank, then add weak deoxidizing alloy, and finally add strong deoxidizing alloy to increase the oxygen content in the steel in the early stage of tapping.

[0014] 3. Control the timing of adding strong deoxidizer: the timing of adding silicon-calcium-barium-iron-iron and aluminum-containing materials is changed from 1 / 3 of tapping time to 1 min before the end of converter tapping to reduce the nitrogen absorption of molten steel dur...

Embodiment 2

[0016] 1. Control the oxygen content of tapping: the carbon weight of tapping is 0.15%, and the oxygen content is controlled at 150ppm.

[0017] 2. Control the order of adding deoxidized alloy: use alloy material tank to add alloy, first add non-deoxidized alloy to the bottom of the tank, then add weak deoxidized alloy, and finally add strong deoxidized alloy to increase the oxygen content in the steel in the early stage of tapping.

[0018] 3. Control the timing of adding strong deoxidizer: Add silicon-calcium-barium-iron and aluminum-containing materials 1 minute before the end of converter tapping to reduce nitrogen absorption in molten steel during tapping.

Embodiment 3

[0020] 1. Control the oxygen content of tapping: when the carbon weight of tapping is 0.30%, the oxygen content is controlled at 600ppm.

[0021] 2. Control the order of adding deoxidized alloy: use alloy material tank to add alloy, first add non-deoxidized alloy to the bottom of the tank, then add weak deoxidized alloy, and finally add strong deoxidized alloy to increase the oxygen content in the steel in the early stage of tapping.

[0022] 3. Control the timing of adding strong deoxidizer: Add silicon-calcium-barium-iron and aluminum-containing materials 1 minute before the end of converter tapping to reduce nitrogen absorption in molten steel during tapping.

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Abstract

The invention provides a method for controlling nitrogen increasing of converter tapping molten steel. When the tapping carbon weight percent is less than 0.10%, the oxygen content is controlled to 300-500ppm; when the tapping carbon weight percent is 0.10-0.20%, the oxygen content is controlled to 100-250ppm; when the tapping carbon weight percent is more than 0.20%, the oxygen content is controlled to 50-100ppm; converter after-deoxidation alloys, namely non-deoxidation alloys, weak-deoxidation alloys and strong-deoxidation alloys are added in turn, thus increasing the oxygen content of steel in the early stage of tapping; and Si-Fe-Ba-Ca and an aluminum-containing material are added 1min before the converter tapping. By adopting the method provided by the invention, the nitrogen increasing amount of the tapping process can be effectively reduced and the nitrogen increasing amount of molten steel in the tapping process is decreased from 6-10ppm to 2ppm or less. Therefore, the quality of the finished steel can be increased and the demands of users on the operational performance can be met.

Description

technical field [0001] The invention belongs to the technical field of steelmaking technology, and in particular relates to a method for preventing molten steel from increasing nitrogen during the tapping process of a converter. Background technique [0002] With the progress of society, the requirements for the performance of steel are also getting higher and higher. Therefore, the lower the content of harmful elements in steel is required, the better. Since the nitrogen element in the steel will cause the "blue embrittlement" phenomenon of the steel and affect the plasticity and toughness of the steel, the nitrogen element is usually controlled as a harmful element in the steel. At present, the methods for reducing the nitrogen weight percentage (referred to as weight) content in steel are mainly divided into two aspects: preventing nitrogen addition or removing nitrogen. However, most of its research focuses on the refining furnace, and there are few studies on the nitr...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C21C5/28C21C7/00
Inventor 宁东高立超徐振东
Owner ANGANG STEEL CO LTD
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