A corrosion-resistant high-strength toughness wear-resistant bainitic steel rail and its production method

Abstract

The invention provides a corrosion-resistant high-strength and toughness wear-resistant bainite steel rail and a production method thereof, wherein the composition of the rail is as follows: 0.10%-0.35% of C, 1.00%-2. 00% of Si, 1.00% to 2.00% of Mn, less than or equal to 0.025 of P, less than or equal to 0.015 of S, 0.50% to 1.50% of Cr, 0.20% to 0.60% of Cu, 0.10% to 0.50% of Ni, 0.0008% to 0.0025% of B, 0.02% to 0.15% of Nb, 0.02% to 0.30% of Sb and balance of Fe and inevitable impurities. The production method is as follows in order: smelting, refining, continuous casting, continuous casting billet heating, initial rolling, universal rolling, and slow cooling, rail tensile strength is greater than or equal to 1390MPa, yield strength is greater than or equal to 1200MPa, the elongation is greater than or equal to 12.5%, normal temperature impact work AKU2 is greater than or equal to 70J, and corrosion resistance is good.

Description

technical field [0001] The invention belongs to the field of metal materials, in particular to a 60kg / m level corrosion-resistant bainitic steel rail used for railways in wet tunnels and marine environments. Background technique [0002] In recent years, with the rapid development of railway transportation, the traction weight, transportation density and transportation range of trains have increased significantly. As the rails that guide trains run, their use environment has become more complex, and the corrosion problems caused by the complex environment have become more and more obvious. Due to the large proportion of mountainous areas in our country, many railways inevitably need to pass through tunnels, and the dark and humid environment in the tunnels will cause serious corrosion to the rails and shorten the service life; Facing marine environment aerosol corrosion. According to the feedback from the Railway Bureau, rail corrosion in these areas has intensified the fr...

AI Technical Summary

Problems solved by technology

However, the amount of alloying elements added in this method is too high, especially the Cr element is as high as 4.0%. The strong hardenability leads to the appearance of martensite after low-speed cooling (such as normalizing), so that the volume fraction in the bainite rail structure is as high as 20%. %~30% martensite, the toughness and plasticity are seriously reduced

The corrosion resistance has been improved, but the performance is no longer available. At the same time, the Mn+Cr exceeds 5.0%, which also significantly reduces the process performance of the rail, the element segregation is intensified, and the production cost soars

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