Process method for smelting high purity steel through VD vacuum treatment device

A technology of vacuum treatment and process method, applied in the direction of manufacturing converters, etc., can solve problems such as inclusions

Active Publication Date: 2020-07-07
JIANGSU LIHUAI IRON AND STEEL CO LTD +1
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  • Description
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  • Application Information

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Problems solved by technology

[0005] The purpose of the present invention is to provide a process method for smelting high-purity steel using VD vacuum treatment equipment, solve the problem o

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  • Process method for smelting high purity steel through VD vacuum treatment device
  • Process method for smelting high purity steel through VD vacuum treatment device
  • Process method for smelting high purity steel through VD vacuum treatment device

Examples

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example 1

[0052] 20CrMo, the mass percentage ω[C] of C in steel is 0.20%, and it is produced by molten iron desulfurization → LD → LF → VD process. Specifically include the following steps:

[0053] 1) Use molten iron with a mass percentage ω[S] of 0.019% of S as raw material, use KR to stir and desulfurize, and the S content of molten iron before entering the furnace is 16ppm;

[0054] 2) Smelting in a 90T top-bottom combined blowing converter, the mass percentage ω[C] of tapping C is 0.08%, the free oxygen content of molten steel is 500ppm when tapping, and the ratio of 1.65kg / t to the furnace before tapping is 30t Add aluminum cake for rapid deoxidation, and the mass percentage ω[Al] of Al at the refining station is 0.067%;

[0055] 3) LF refining slagging: add lime and pre-melted refining slag each 500kg / furnace to make slagging, LF refining process uses silicon carbide to deoxidize the slag surface, the dosage is 180kg / furnace, uses quartz sand 200kg / furnace to adjust the slag com...

example 2

[0061] 20CrMo, the mass percentage ω[C] of C in steel is 0.20%, and it is produced by molten iron desulfurization → LD → LF → VD process. Specifically include the following steps:

[0062] 1) Use molten iron whose mass percentage ω[S] of S is 0.021% as raw material, use KR to stir and desulfurize, and the S content of molten iron before entering the furnace is 20ppm;

[0063] 2) Smelting in a 90T top-bottom double-blown converter, the mass percentage ω[C] of tapping C is 0.10%, the free oxygen content of molten steel is 330ppm when tapping, and the ratio of 1.49kg / t to the furnace before tapping is 30t Add aluminum cake for rapid deoxidation, and the mass percentage ω[Al] of Al at the refining station is 0.071%;

[0064] 3) LF refining slagging: add lime and pre-melted refining slag each 500kg / furnace to make slagging, LF refining process uses silicon carbide to deoxidize the slag surface, the dosage is 170kg / furnace, uses quartz sand 200kg / furnace to adjust the slag composit...

example 3

[0070] 20CrMo, the mass percentage ω[C] of C in steel is 0.20%, and it is produced by molten iron desulfurization → LD → LF → VD process. Specifically include the following steps:

[0071] 1) Using molten iron with a mass percentage of S ω[S] of 0.022% as raw material, using KR to stir and desulfurize, the S content of the molten iron before entering the furnace is 19ppm;

[0072]2) Smelting in a 90T top-bottom double-blown converter, the mass percentage ω[C] of tapping C is 0.11%, the free oxygen content of molten steel is 310ppm when tapping, and the ratio of 1.43kg / t to the furnace before tapping is 30t Add aluminum cake for rapid deoxidation, and the mass percentage ω[Al] of Al at the refining station is 0.073%;

[0073] 3) LF refining slagging: add lime and pre-melted refining slag each 500kg / furnace to make slagging, LF refining process uses silicon carbide to deoxidize the slag surface, the dosage is 160kg / furnace, uses quartz sand 200kg / furnace to adjust the slag comp...

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Abstract

The invention provides a process method for smelting high purity steel through a VD vacuum treatment device. The method comprises the following steps of KR molten iron desulfuration, wherein it is ensured that before putting into a furnace, S in molten iron is smaller than or equal to 30 ppm; top and bottom combined blowing converter blowing, wherein the mass percent omega [C] of converter tappingC is larger than or equal to 0.08%; external refining and argon refining, wherein in the full process, weak stirring is carried out, and calcium aluminum silicon series slag with the basicity being 2.0 to 4.5 is adopted; and VD treatment, wherein 20 to 35 min VD treatment is adopted, high-vacuum holding of strength is achieved, in the treatment process, according to the strong-weak-strong mode, the bottom stirring argon strength is controlled in a time interval manner, after VD vacuum breaking, a manner that soft blowing is adopted, large-particle inclusions are removed, molten steel is subjected to standing, and small particle inclusions are removed is adopted for further improving the molten steel purity. It is known that through the particular VD treatment process stirring control modeis adopted for assisting with a proper refining slag system and a soft blowing operation method, molten steel slag entrapment can be effectively reduced, the removing effect of non metal inclusions can be improved, and the method is suitable for production of various low, middle and high carbon steel with the carbon content being 0.15 to 1.05%.

Description

technical field [0001] The invention relates to the field of steelmaking technology, in particular to a method for smelting high-purity steel using VD vacuum treatment equipment. Background technique [0002] High-end special steel is a key material required for major equipment manufacturing and national key projects. It is widely used in aviation, automobiles, construction machinery, energy mining, railway transportation and many other fields. Its quality control level represents a country's industrialization development level and manufacturing industry. strong and weak. White spots in steel, that is, hydrogen-induced cracks, are one of the most harmful defects in steel. Once they occur without effective rescue measures, they often lead to direct scrapping of steel parts. They are defects that should be avoided in the process of steel production. The purity control level of molten steel such as non-metallic inclusions, total oxygen content, and residual hydrogen content in...

Claims

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Application Information

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IPC IPC(8): C21C7/064C21C5/35C21C7/06C21C7/10C21C7/072
CPCC21C5/35C21C7/06C21C7/064C21C7/072C21C7/10
Inventor 翟万里印传磊郑力宁田春阳李润张洪才林鹏刘从德蒋栋初徐亚鹏
Owner JIANGSU LIHUAI IRON AND STEEL CO LTD
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