High-strength delayed fracture-resistant hot-rolled steel rail and manufacturing method thereof

A delayed fracture and rail technology, applied in the direction of metal rolling, etc., to achieve the effect of improving impact toughness at room temperature, widely used, and improving the delayed fracture resistance of rails

Active Publication Date: 2021-01-29
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

my country's existing high-speed railways mainly use pearlitic hot-rolled steel rails. In the fiercely competitive existing technologies, manufacturers mainly use micro-alloying, controlled rolling and controlled cooling to improve the comprehensive performance of pearlitic steel rails. However, through On-line continuous cooling of continuous casting slabs to improve the delayed fracture resistance of hot-rolled rails has rarely been reported

Method used

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  • High-strength delayed fracture-resistant hot-rolled steel rail and manufacturing method thereof
  • High-strength delayed fracture-resistant hot-rolled steel rail and manufacturing method thereof

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0068] This example is used to illustrate the specific preparation process of the hot-rolled rail.

[0069]Furnace material is smelted into molten steel through converter smelting or electric furnace smelting, aluminum-free deoxidation, LF refining, RH vacuum treatment or VD vacuum treatment, continuous casting of molten steel into billet, continuous cooling of billet, heating of billet in heating furnace, online rolling into rail, straightening Straightening, flaw detection and processing;

[0070] Wherein, the billet continuous cooling process includes the following steps:

[0071] (1) The first stage of cooling: the steel billet with a surface temperature of 870°C is cooled in the first stage, and the billet is cooled to a surface temperature of 470°C at a cooling rate of 0.6°C / s;

[0072] (2) Second-stage cooling: the steel billet with a surface temperature of 470°C is cooled in the second stage, and the billet is cooled to a surface temperature of 220°C at a cooling rate...

Embodiment 2

[0078] This example is used to illustrate the specific preparation process of the hot-rolled rail.

[0079] Furnace material is smelted into molten steel through converter smelting or electric furnace smelting, aluminum-free deoxidation, LF refining, RH vacuum treatment or VD vacuum treatment, continuous casting of molten steel into billet, continuous cooling of billet, heating of billet in heating furnace, online rolling into rail, straightening Straightening, flaw detection and processing;

[0080] Wherein, the billet continuous cooling process includes the following steps:

[0081] (1) The first stage of cooling: the steel billet with a surface temperature of 850°C is cooled in the first stage, and the billet is cooled to a surface temperature of 450°C at a cooling rate of 0.7°C / s;

[0082] (2) Second-stage cooling: the steel billet with a surface temperature of 450°C is cooled in the second stage, and the billet is cooled to a surface temperature of 200°C at a cooling rat...

Embodiment 3

[0088] This example is used to illustrate the specific preparation process of the hot-rolled rail.

[0089] Furnace material is smelted into molten steel through converter smelting or electric furnace smelting, aluminum-free deoxidation, LF refining, RH vacuum treatment or VD vacuum treatment, continuous casting of molten steel into billet, continuous cooling of billet, heating of billet in heating furnace, online rolling into rail, straightening Straightening, flaw detection and processing;

[0090] Wherein, the billet continuous cooling process includes the following steps:

[0091] (1) The first stage of cooling: the steel billet with a surface temperature of 830°C is cooled in the first stage, and the billet is cooled to a surface temperature of 420°C at a cooling rate of 0.8°C / s;

[0092] (2) Second-stage cooling: the steel billet with a surface temperature of 420°C is cooled in the second stage, and the billet is cooled to a surface temperature of 180°C at a cooling rat...

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Abstract

The invention relates to the technical field of steel rail manufacturing, and discloses a high-strength delayed fracture-resistant hot-rolled steel rail and a manufacturing method thereof. The methodcomprises the steps of converter or electric furnace smelting, aluminum-free deoxidation, LF refining, RH or VD vacuum treatment, continuous casting, continuous cooling, heating furnace heating, online rolling and aftertreatment. The steel billet continuous cooling process comprises the following steps: (1) carrying out first-stage cooling on a steel billet with the surface temperature of 830-900DEG C, and cooling the steel billet to the surface temperature of 350-500 DEG C at the cooling rate of 0.3-1.3 DEG C / s; (2) carrying out second-stage cooling on the steel billet, and cooling the steelbillet to the surface temperature of 150-250 DEG C at the cooling rate of 0.2-1 DEG C / s; and (3) carrying out third-stage cooling on the steel billet, and cooling the steel billet to the surface temperature of 50-150 DEG C at the cooling rate of 0.1-0.8 DEG C / s. The delayed fracture resistance of the obtained hot-rolled steel rail is remarkably improved.

Description

technical field [0001] The invention relates to the technical field of rail preparation, in particular to a high-strength delayed-fracture-resistant hot-rolled rail and a preparation method thereof. Background technique [0002] The development of high-speed and heavy-haul railways has put forward higher requirements for the comprehensive service performance of rails. With the further requirements for driving safety, abnormal fatigue, excessive wear and sudden fracture of rails in service have been strictly restricted. my country's existing high-speed railways mainly use pearlitic hot-rolled steel rails. In the fiercely competitive existing technologies, manufacturers mainly use micro-alloying, controlled rolling and controlled cooling to improve the comprehensive performance of pearlitic steel rails. However, through There are few reports on the continuous cooling of continuous casting slabs on-line to improve the delayed fracture resistance of hot-rolled rails. [0003] T...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): B22D11/22B21B1/085C22C38/02C22C38/04C22C38/28
CPCB21B1/085B22D11/225C22C38/02C22C38/04C22C38/28
Inventor 杨大巍邓勇邹明李晓煜
Owner PANZHIHUA IRON & STEEL RES INST OF PANGANG GROUP
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