Method for controlling center segregation of large-section heavy rail steel slab

A heavy-gauge steel and large-section technology, applied in the field of iron and steel metallurgy, can solve problems such as shrinkage porosity and segregation, and achieve the effects of central segregation control and internal quality assurance

Inactive Publication Date: 2016-01-06
PANZHIHUA IRON & STEEL RES INST OF PANGANG GROUP
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, some key specific technologies for the central segregation control of large-section heavy rail steel continuous casting slabs have not been involved.
[0005] CN102806330A discloses a method for improving the internal quality of thick and large-section continuous casting slabs, which can solve the problems of shrinkage cavity porosity and segregation in the center of medium-thick and large-section continuous casting slabs in the prior art

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0012] This embodiment is that a steelmaking plant adopts the technical method of the present invention to produce large-section (320mm*410) heavy rail steel U75V continuous casting slabs. The actual control of the production process is as follows: after the vacuum treatment, the exit temperature of the molten steel is 57°C to 65°C higher than the liquidus temperature, and the exit temperature of the first furnace of the tundish is 73°C. The actual superheat control range of molten steel in the tundish is 26°C to 35°C, with an average of 29°C. During the pouring process, the normal casting speed is controlled at 0.65m / min~0.72m / min, and the proportion of 0.70m / min (constant speed pouring) is up to 82.1%. The actual depression at the end of solidification is 11.2mm. The stirring intensity of the electromagnetic stirring of the crystallizer is set to 450A, and the stirring frequency is 2.4Hz; the stirring intensity of the electromagnetic stirring at the solidification end is se...

Embodiment 2

[0015] This embodiment is that a steelmaking plant adopts the technical method of the present invention to produce large-section (320mm*410) heavy rail steel U71Mn continuous casting slabs. The actual control of the production process is as follows: after the vacuum treatment, the exit temperature of the molten steel is 55°C to 64°C higher than the liquidus temperature, and the exit temperature of the first heat of the tundish molten steel is 73°C. The actual superheat control range of the molten steel in the tundish is 25°C to 33°C, with an average of 31°C. During the pouring process, the normal casting speed is controlled at 0.68m / min to 0.75m / min, and the ratio of maintaining 0.70m / min (constant speed pouring) reaches 80.7%. The actual depression at the end of solidification is 10.2mm. The stirring intensity of the electromagnetic stirring of the crystallizer is set to 350A, and the stirring frequency is 2.4Hz; the stirring intensity of the electromagnetic stirring at the ...

Embodiment 3

[0018] This embodiment is that a steelmaking plant adopts the technical method of the present invention to produce large-section (320mm*410) heavy rail steel U78CrV continuous casting slabs. The actual control of the production process is as follows: after the vacuum treatment, the exit temperature of the molten steel is 57°C to 63°C higher than the liquidus temperature, and the exit temperature of the first heat of the tundish molten steel is 74°C. The actual superheat control range of molten steel in the tundish is 26°C to 34°C, with an average of 33°C. During the pouring process, the normal casting speed is controlled at 0.66m / min to 0.74m / min, and the ratio of 0.70m / min (constant speed pouring) is 81.8%. The actual depression at the end of solidification is 13.8mm. The stirring intensity of the electromagnetic stirring of the crystallizer is set to 400A, and the stirring frequency is 2.4Hz; the stirring intensity of the electromagnetic stirring at the solidification end i...

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PUM

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Abstract

The invention relates to a method for controlling center segregation of a large-section heavy rail steel slab and belongs to the field of ferrous metallurgy. According to the technical scheme, during the pouring process, the degree of superheat of poured molten steel is 25-35 DEG C, the pulling rate is 0.65 m/min-0.75 m/min, and the solidification tail end of the steel slab is pressed down by 10-14 mm; during the continuous casting process, the electromagnetic stirring strength at a crystallizer is 350-450 A, the stirring frequency is 2.3-2.5 Hz, the electromagnetic stirring strength at the solidification tail end is set to 350-450 A, and the stirring frequency is 6.8-7.2 Hz. According to the method, through controlling the degree of superheat, the pouring rate and the solidification tail end pressing of the poured molten steel, and by combining reasonable selection of the electric stirring mode and the electric stirring parameter, the center segregation of the large-section heavy rail steel slab is effectively controlled, and the rest inner quality of the steel slab is effectively guaranteed.

Description

technical field [0001] The invention relates to a method for controlling the central segregation of a large-section heavy rail steel slab, belonging to the field of iron and steel metallurgy. Background technique [0002] Steel rails are the main components of railway tracks. During railway transportation, to provide effective support and guidance for locomotives, they need to bear huge vertical pressure from wheels. Based on the development needs of my country's infrastructure construction, railway transportation is developing at a rapid speed, and it is becoming more and more high-speed and heavy-duty. The size of rails is also gradually increasing. In order to reduce welded joints and ensure higher integrity of railway rails, the length of large-size rails is also increasing. The rolling of large-size and long-length rails with smaller cross-section slabs undoubtedly requires longer slab lengths, which requires a major transformation of subsequent heat treatment equipmen...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): B22D11/18B22D11/115
Inventor 陈天明李红光陈亮
Owner PANZHIHUA IRON & STEEL RES INST OF PANGANG GROUP
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