Blowing powder for molten steel secondary refining and preparation method and methods for using same

A technology for external refining and molten steel furnace, which is applied in the field of injection powder for external refining of molten steel and its preparation and application. It can solve the problems of insufficient matching of smelting time and affect the production efficiency of steelmaking process, etc., and achieve shortening of operation time and improvement of operation. Efficiency, the effect of reducing production costs

Inactive Publication Date: 2009-10-07
INST OF METALLURGICAL TECH DONGBEI UNIV SHENYANG
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0003] In order to solve the problem that the LF furnace refining equipment does not match the converter continuous casting in terms of smelting time, which seriously affects the production efficiency of the steelmaking process, it is also to obtain better smelting effects, produce more high-quality alloy steel, and meet the needs of the society. The increasing new requirements of metal materials, the applicant of the present invention, after years of research, invented the method of directly spraying calcium aluminate powder into molten steel to carry out reverse refining slag washing of molten steel during the refining process outside the furnace, and developed products required for spraying

Method used

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  • Blowing powder for molten steel secondary refining and preparation method and methods for using same

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0024] The slab is produced on a 150-ton converter in the A steel plant. The steel type is STSC, and the tapping temperature is 1670°C. After aluminum deoxidation and alloying in the ladle, the average oxygen in the steel is 25ppm, and the sulfur is 260ppm. The direct injection powder refining process is adopted. Its calcium-calcium aluminate powder mass ratio is: Ca: 20%, calcium aluminate is 80%, the Al in this calcium aluminate 2 o 3 The CaO content is 38%, and the CaO content is 62%. The calcium-calcium aluminate composite powder of the above components is sprayed into molten steel. The test results are counted for 100 furnaces, and the powder dosage is 1.0kg / t steel; ladle sampling analysis [O] content It is 8.9ppm, [S] content is 185ppm, so the content of oxygen and sulfur in steel after molten steel refining according to this technology is better than that of traditional LF furnace refining.

Embodiment 2

[0026] The slab is produced on a 150-ton converter in the A steel plant. The steel type is STSC, and the tapping temperature is 1670°C. After aluminum deoxidation and alloying in the ladle, the average oxygen in the steel is 25ppm, and the sulfur is 260ppm. The direct injection powder refining process is adopted. Its calcium-calcium aluminate powder mass ratio is: Ca: 1%, calcium aluminate content is 99%, the Al in this calcium aluminate 2 o 3 The CaO content is 50%, and the calcium-calcium aluminate composite powder of the above components is sprayed into molten steel. The test results are counted for 100 furnaces, and the powder dosage is 1.0kg / t steel; the ladle is sampled to analyze the [O] content It is 8.9ppm, [S] content is 185ppm, so the content of oxygen and sulfur in steel after molten steel refining according to this technology is better than that of traditional LF furnace refining.

Embodiment 3

[0028] The slab is produced on a 150-ton converter in the A steel plant. The steel type is STSC, and the tapping temperature is 1670°C. After aluminum deoxidation and alloying in the ladle, the average oxygen in the steel is 25ppm, and the sulfur is 260ppm. The direct injection powder refining process is adopted. Its calcium-calcium aluminate powder mass ratio is: Ca: 48%, calcium aluminate content is 52%, the Al in this calcium aluminate 2 o 3 The CaO content is 60%, and the CaO content is 40%. The calcium-calcium aluminate composite powder of the above components is sprayed into molten steel. The test results are counted for 100 furnaces, and the powder dosage is 1.0kg / t steel; the ladle is sampled to analyze the [O] content It is 8.9ppm, [S] content is 185ppm, so the content of oxygen and sulfur in steel after molten steel refining according to this technology is better than that of traditional LF furnace refining.

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Abstract

A method for molten steel secondary refining by means of blowing powder is characterized in that the blowing powder is formed through mixing passivated calcium aluminate powder and calcium metal powder according to a certain proportion; the mass percent of the chemical composition of the powder is as follows: Ca is more than or equal to 1 and is less than or equal to 48, while calcium aluminate is more than or equal to 52 and is less than or equal to 99; moreover, both the particle sizes of the calcium metal powder and the calcium aluminate powder are less than or equal to 1.5 mm. During blowing, single blowing of calcium aluminate powder, or mixing blowing of mixed calcium metal powder and calcium aluminate powder, or compound blowing process of calcium metal and calcium aluminate can be adopted. The method can replace LF furnace process in molten steel secondary refining; moreover, the method substantially saves secondary refining time, increases utilization rate of calcium metal and obtains ideal refining effect.

Description

technical field [0001] The invention relates to a method for refining molten steel outside a furnace by using injection powder, the required powder and its preparation. Background technique [0002] At present, in steelmaking production, most enterprises adopt the technological process of molten iron pretreatment-converter (or electric furnace) smelting-out-of-furnace refining-continuous billet casting. The out-of-furnace refining methods in the process include LF, VD, RH plus argon blowing and stirring There are several ways, among which the LF furnace process was used earlier and more widely. The main purpose of using LF furnace for out-of-furnace refining is to increase the temperature of molten steel and slagging and refining to remove inclusions in molten steel, including further desulfurization and deoxidation of molten steel. However, with the shortening of the converter smelting time and the substantial increase of the billet casting speed in the continuous billet c...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C21C7/04
CPCY02P10/20
Inventor 孙中强
Owner INST OF METALLURGICAL TECH DONGBEI UNIV SHENYANG
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