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Steel rails resistant to corrosion in marine environments

A marine environment and rail technology, applied in the field of rail materials, can solve the problems of deterioration of welding performance, heat welding impact toughness, difficulty in meeting large axle loads, heavy-duty and heavy-duty railway transportation needs, and the tendency to increase copper brittleness, etc., to achieve The effect of good mechanical properties

Active Publication Date: 2016-04-06
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

First of all, the Cr content is a strengthening element commonly used in rail steel at present. Increasing the Cr content not only significantly improves the strength and toughness, but also improves the corrosion resistance; adding 0.2% to 0.65% of Cu and adding 0.1% to 0.3% of Cu as required Ni can slightly improve the strength and hardness index of the rail without losing ductility and plasticity; for corrosion resistance, if the P content in steel is ≤0.025%, its contribution to the improvement of the corrosion resistance of the rail is limited
At the same time, when the Cu content exceeds 0.5%, it will also cause the deterioration of welding performance, especially the impact toughness of aluminothermic welding, and increase the tendency of copper embrittlement, which is not conducive to the service safety of rails.
In addition, the upper limit of the carbon content in this patent is 0.72%, and the hot-rolled steel rails are used directly on the road. Heavy-haul rail transport demand

Method used

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  • Steel rails resistant to corrosion in marine environments
  • Steel rails resistant to corrosion in marine environments
  • Steel rails resistant to corrosion in marine environments

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0028] Steel rails resistant to corrosion in marine environments, the chemical composition of which is C: 0.71%, Si: 0.69%, Mn: 0.92%, Cr: 0.20%, V: 0.08, Cu: 0.38%, Ni: 0.20%, P: 0.030%, S: ≤0.015%, the balance is Fe and unavoidable impurities.

[0029] The molten steel containing the above components is smelted in a converter or an electric furnace. After refining outside the furnace and vacuum degassing, it is continuously cast into a bloom and then sent to a heating furnace for heating and heat preservation. It is rolled into a single weight of 50-75kg by pass method or universal method. / m rail, using the waste heat of the rail, apply 2.8°C / s cooling medium to the rail head tread and both sides of the rail head respectively. When the rail head tread temperature drops to 465°C, stop the accelerated cooling and air cool to room temperature.

[0030] The steel rail prepared by the above method was tested for microstructure, pearlite lamellar spacing, normal temperature tensi...

Embodiment 2～ Embodiment 6

[0041] The chemical composition and heat treatment process parameters of the steel in Example 1 were changed, and Example 2 to Example 6 were carried out.

[0042] Table 1 has listed the chemical composition of the billet of embodiment 1~6, and table 2 has listed the heat treatment process control parameter (comprising accelerated cooling rate and final cooling temperature) of embodiment 1~6, and table 3 has listed embodiment 1 ~6 performance test results (including microstructure, pearlite plate spacing, tensile strength Rm, elongation A and corrosion rate).

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Abstract

The invention relates to a steel rail material, and in particular relates to a marine environment corrosion-resistant steel rail. The technical problem to be solved by the invention is to provide a marine environment corrosion-resistant steel rail. The marine environment corrosion-resistant steel rail is prepared by adopting a heat treatment method comprising the following steps: performing accelerated cooling on the steel rail which is subjected to hot rolling and is positioned in an austenitic phase area at a cooling speed of 2-5 DEG C / s; stopping accelerated cooling until the temperature of a rail head tread is reduced to be less than 480 DEG C, and air-cooling to room temperature to obtain a steel rail finished product, wherein a microscopic structure of the steel rail finished product is a pearlite consisting of lamellar ferrites and cementite alternately distributed among the lamellar ferrites; the separation distance among pearlite sheets is not more than 120nm; the tensile strength of the steel rail finished product is more than or equal to 1200MPa, and the elongation percentage of the steel rail finished product is more than or equal to 10%. The steel rail disclosed by the invention is capable of resisting marine environment corrosion, has a corrosion rate of less than 1 / 2 of that of carbon and ordinary microalloyed steel rails under equal conditions in a marine environment, and is suitable for application in heavy haul railways with high transportation capacity and high axle load in coastal regions.

Description

technical field [0001] The invention relates to a steel rail material, in particular to a steel rail resistant to marine environment corrosion. Background technique [0002] As a structural member that guides the train to run and transmits the load to the ballast bed, the rail is directly related to the transportation efficiency and driving safety of the railway. Because railways are exposed to the natural environment for a long time, the steel used for railways must not only meet the requirements of various mechanical properties, but also have certain corrosion resistance. During the service process of rails, they not only have to bear various complex stresses, but also face failure problems caused by long-term corrosion. The southeast coast of my country has dense railways, high traffic density, and high total weight. Due to the long-term service in the marine environment, the rails are seriously corroded. On the basis of ensuring the required mechanical properties, the c...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C21D8/00C22C38/46
Inventor 韩振宇邹明郭华李大东贾济海邓勇王春建袁俊陈崇木
Owner PANZHIHUA IRON & STEEL RES INST OF PANGANG GROUP