Steel rail for heavy-duty railway and preparation method thereof

A technology for steel rails and railways, applied in the field of steel rails for heavy-duty railways and its preparation, can solve the problems of low longitudinal fracture toughness of the lower jaw, achieve excellent longitudinal fracture toughness, and improve strength and toughness

Active Publication Date: 2022-05-24
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

[0005] The purpose of the present invention is to overcome the problem of low longitudinal fracture toughness of the rail head of the heavy-duty railway existing in the prior art, and provide a kind of steel rail for the heavy-duty railway and its preparation method. Refine the spacing of pearlite sheets to a certain extent, and improve the strength and toughness of the lower jaw of the rail

Method used

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  • Steel rail for heavy-duty railway and preparation method thereof
  • Steel rail for heavy-duty railway and preparation method thereof

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preparation example Construction

[0023] One aspect of the present invention provides a method for preparing a heavy-duty railway rail, the method comprising the following steps:

[0024] (1) hot-rolling the billet after the heat preservation treatment to obtain a waste heat rail, and performing accelerated cooling on the lower jaw part of the rail head of the waste heat rail, the cooling temperature of the accelerated cooling is 650-800 ° C, and the cooling rate of the accelerated cooling is 1.5- 2.5℃ / s, stop accelerated cooling when the temperature drops to 380-420℃;

[0025] (2) cooling the rail that stops accelerated cooling in step (1) to room temperature;

[0026] Wherein, in step (1), the steel billet contains 0.75-0.95 wt % C, 0.45-0.6 wt % Si, 0.8-1.1 wt % Mn, 0.05-0.2 wt % V, and the balance is Fe and inevitable impurities.

[0027] Carbon (C) is the most important element for obtaining good strength-toughness matching and comprehensive mechanical properties in heavy-duty railway rail steels. In o...

Embodiment 1

[0045] (1) The billet is sent to the walking furnace for heating and heat preservation, the temperature of heat preservation is 1250℃, and the time of heat preservation is 4h, and then the steel billet after heat preservation treatment is hot rolled by the universal method to obtain a unit weight of 75kg / m The waste heat rail is accelerated to cool the lower jaw part of the rail head of the waste heat rail. The start-up cooling temperature of the accelerated cooling is 677°C, the cooling rate of the accelerated cooling is 1.97°C / s, and the accelerated cooling is stopped when the temperature drops to 404°C;

[0046] (2) the rail that stops accelerated cooling in step (1) is cooled to room temperature in air to obtain rail A1;

[0047] Wherein, in step (1), the steel billet contains 0.85 wt % C, 0.57 wt % Si, 0.97 wt % Mn, 0.13 wt % V, and the balance is Fe and inevitable impurities.

Embodiment 2

[0049] (1) The billet is sent into the walking furnace for heating and heat preservation, the temperature of heat preservation is 1300℃, and the time of heat preservation is 2h, and then the steel billet after heat preservation treatment is hot rolled by the universal method to obtain a unit weight of 75kg / m The waste heat rail is accelerated to cool the lower jaw part of the rail head of the waste heat rail. The start-up cooling temperature of the accelerated cooling is 703°C, the cooling rate of the accelerated cooling is 2.21°C / s, and the accelerated cooling is stopped when the temperature drops to 398°C;

[0050] (2) the steel rail that stops accelerated cooling in step (1) is cooled to room temperature in air to obtain steel rail A2;

[0051] Wherein, in step (1), the steel billet contains 0.85 wt % C, 0.59 wt % Si, 0.96 wt % Mn, 0.15 wt % V, and the balance is Fe and inevitable impurities.

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Abstract

The invention relates to the field of rail materials, and discloses a rail for heavy-duty railways and a preparation method thereof. The method comprises the following steps: (1) hot rolling the heat-insulating steel slab to obtain a waste heat rail, performing accelerated cooling on the lower jaw of the rail head of the waste heat rail, the accelerated cooling starting temperature is 650-800°C, The cooling rate is 1.5-2.5°C / s, and when the temperature drops to 380-420°C, the accelerated cooling is stopped; (2) the steel rail whose accelerated cooling is stopped in step (1) is cooled to room temperature. The method can refine the spacing of pearlite sheets to a certain extent through accelerated cooling treatment, and improve the strength and toughness of the lower jaw of the rail.

Description

technical field [0001] The invention relates to the field of steel rail materials, in particular to a steel rail for heavy-duty railways and a preparation method thereof. Background technique [0002] With the rapid development of the national economy, the railway transportation is increasingly busy, and the freight and heavy-haul railway is the main artery of my country's economic development. my country's railway freight has the characteristics of large axle load, large transportation volume, and complex geographical environment. For example, the Daqin Railway train axle load reaches 25t, the maximum single train transportation volume reaches 20,000 tons, the single-day transportation volume reaches 1.37 million tons, and the annual transportation volume is close to 500 million tons. With the increase of train axle load and running density, the service conditions of heavy-duty railway rails are getting worse. [0003] Rail fractures often occur on heavy-duty lines due to ...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C21D9/04C21D6/00C22C38/02C22C38/04C22C38/12
CPCC21D9/04C21D6/008C21D6/005C22C38/02C22C38/04C22C38/12C21D2211/009
Inventor 汪渊邹明宁雄显陈崇木
Owner PANZHIHUA IRON & STEEL RES INST OF PANGANG GROUP
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