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Process for removing non-metallic inclusions in molten steel

A technology for non-metallic inclusions and molten steel, which is applied to the process of removing non-metallic inclusions in molten steel and the technical field of removing inclusions in molten steel. The inclusions are fully floated, the continuous casting plug rod is seriously corroded, etc., to achieve the effect of easy control of the process, less investment, and reduced total amount

Active Publication Date: 2012-02-01
SHOUGANG CORPORATION
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The argon blowing time of 3 minutes is short, and the inclusions cannot be fully floated; moreover, the flow rate of the feeding line is always 100-200NL / min, and the flow rate during the feeding line is too small, which is not conducive to the rapid diffusion of Ca in the fed steel
This method has high calcium content, which seriously corrodes the continuous casting plug rod, which is not conducive to continuous casting in multiple furnaces.

Method used

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  • Process for removing non-metallic inclusions in molten steel
  • Process for removing non-metallic inclusions in molten steel
  • Process for removing non-metallic inclusions in molten steel

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0033] The specific implementation process is to produce 10 furnaces in a single casting time, and adopt the process route of "converter-LF refining-continuous casting" to produce high-grade hot-rolled steel.

[0034] 300 tons of top-bottom double-blowing converter steelmaking, the actual control data of ladle bottom-blowing argon gas agitation after tapping is shown in Table 1; then the secondary refining treatment in LF furnace is carried out, and the components included in the ladle top slag after refining are shown in Table 2 Show. At the end of refining, soft blowing is performed once, and after soft blowing, silicon-calcium wire with a diameter of Φ13mm is fed. After the wire is fed, soft blowing is performed for the second time, and full protection casting is carried out after soft blowing. The specific process parameters of two soft blowing and wire feeding are shown in Table 3. See Table 4 and Table 5 for the actual control of molten steel composition during the two ...

Embodiment 2

[0048] 11 furnaces of hot-rolled steel grades are produced in a single cast, and high-grade hot-rolled steel grades are produced using the 'converter-RH refining-continuous casting' process route.

[0049] The top slag is modified during the tapping process of the 300-ton top-bottom double-blowing converter. The ingredients included are shown in Table 7. At the end of refining, a soft blowing is performed, and after the soft blowing, a silicon-calcium wire with a diameter of Φ13mm is fed. After the wire is fed, a second soft blowing is performed, and after the soft blowing is completed, full-protection casting is carried out. The specific process parameters of the two soft blowing and wire feeding are shown in Table 8. See Table 9 and Table 10 for the actual control of molten steel composition during the two soft blowing and silicon-calcium wire feeding processes.

[0050] Table 6 Ladle stirring after tapping

[0051]

[0052] Table 7 Final composition of ladle top slag ...

Embodiment 3

[0061] 12 furnaces of hot-rolled steel are produced in a single cast, and high-grade hot-rolled steel is produced using the process route of 'converter-LF refining-RH refining-continuous casting'.

[0062] 300 tons of top-bottom double-blowing converter steelmaking, the actual control data of ladle bottom-blowing argon stirring after tapping is shown in Table 11, and then the LF furnace refining treatment is carried out, and then the RH vacuum refining treatment is carried out. After refining, the ladle top slag includes The composition is shown in Table 12. After the RH breaks the vacuum, it starts to perform a soft blowing. After the soft blowing, it feeds the silicon-calcium wire with a diameter of Φ13mm. After feeding the wire, it performs a second soft blowing. The specific process parameters of two soft blowing and wire feeding are shown in Table 13. See Table 14 and Table 15 for the actual control of molten steel composition during the two soft blowing and silicon-calc...

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Abstract

The invention relates to a process for removing non-metallic inclusions in molten steel. The process comprises the following steps of: placing the molten steel into a top-bottom combined blowing converter for performing smelting, then performing steel tapping, adding granular lime and fluorite in the steel tapping process, adding a sustained-release deoxidizing agent on the slag surface at the end of the steel tapping, and blowing argon from the bottom of a ladle for stirring after the end of the steel tapping; performing secondary refining on the molten steel; and sequentially performing primary soft blowing stirring, feeding of a silicon-calcium wire after reaching a wire feeding position and secondary soft blowing stirring on the molten steel after refining, and then performing the continuous casting step for full-protection casting. In the invention, the primary soft blowing is performed after the end of the secondary refining, thereby improving the Als / Alt ratio of the molten steel; and then the silicon-calcium wire is fed, and the secondary soft blowing is further performed for further improving the Als / Alt ratio, thereby being capable of effectively controlling the type B inclusions, being low in input of consumptive raw materials, being capable of realizing multi-converter continuous casting and the like.

Description

technical field [0001] The invention relates to a process for removing inclusions in molten steel, in particular to a process for removing non-metallic inclusions in molten steel, belonging to the field of steel refining control. Background technique [0002] In recent years, the requirements for non-metallic inclusions in hot-rolled plates have become increasingly strict due to their special purposes such as oil transportation, natural gas transportation, high-pressure resistance, and high fatigue. Type A non-metallic inclusions in steel MnS inclusions and Type B alumina inclusions The performance damage to the hot-rolled plate is more prominent. The current steelmaking process can control and stabilize the A-type MnS inclusions through the low-sulfur and calcium treatment process. In the production process, it is the B-type inclusions that affect the pass rate of hot-rolled coils more often. In order to meet the quality requirements of hot-rolled steel and improve the rea...

Claims

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Application Information

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IPC IPC(8): C21C7/072C21C7/076C21C7/06
CPCY02P10/20
Inventor 王志鹏田志红朱立新王松涛庞在钢李一丁王毅张功焰罗伯钢魏钢李越刘建华郭亮彭国仲单庆林赵长亮王朝彬黄财德周伟蒋理王绍峰
Owner SHOUGANG CORPORATION