High-strength weather-proof bridge steel and preparation method thereof

Abstract

The invention discloses high-strength weather-proof bridge steel. The high-strength weather-proof bridge steel is composed of, by mass, 0.03-0.06% of C, 0.20-0.50% of Si, 0.70-1.00% of Mn, 0-0.030% of P, 0-0.003% of S, 0.25-0.60% of Cu, 0.18-0.45% of Ni, 0.30-0.70% of Cr, 0.030-0.080% of Nb, 0-0.010% of Als and the balance Fe and inevitable impurities. Meanwhile, the corresponding elements meet the requirements that 0.6<=[Ni] / [Cu]<=1.5, and 0.80%<=[Cr]+[Cu]+[Ni] / 3<=1.30%. Raw materials are obtained through the steps of smelting, continuous casting, rolling and stacking for slow-cooling. The high-strength weather-proof bridge steel has the advantages of being high in strength, excellent in low-temperature tenacity, low in yield ratio, excellent in welding performance and good in weather-proof performance.

Description

technical field [0001] The invention relates to the technical field of special iron and steel smelting, and specifically relates to a high-strength weather-resistant bridge steel and a preparation method thereof. Background technique [0002] With the rapid development of my country's railway construction, various long-span bridges across rivers and canyons have emerged. The demand for bridge steel is increasing. At the same time, stricter requirements are put forward for the performance of bridge steel. The steel not only has high strength , low temperature toughness and good weldability, but also requires a low yield ratio and a certain weather resistance. A low yield ratio indicates that the steel has good plastic deformation ability, which is an important index to measure the seismic performance of bridge steel. Excellent weather resistance indicates that the steel has good atmospheric corrosion resistance, which can significantly reduce the maintenance cost of the bridg...

AI Technical Summary

Problems solved by technology

[0006] Patent CN200810046963.X discloses an ultra-low carbon hot-rolled weathering steel, which is designed with ultra-low carbon components and has good low-temperature toughness and welding performance, but its Mn content reaches 1.50-1.90%, and it is easy to produce bands in the steel tissue, causing anisotropy, uneven tissue structure

[0007] To sum up, the existing bridge steel has problems such as insufficient strength, poor weather resistance, insufficient low temperature toughness and high yield strength ratio.

Images