Weathering steel with yield strength of 550MPa level and manufacturing method thereof

Abstract

The invention relates to weathering steel with the yield strength of 550MPa level and the advantages of excellent toughness and high corrosion resistance, and a manufacturing method thereof. The weathering steel comprises the following components: 0.02 to 0.08wt% of C, 0.15 to 0.55wt% of Si, 0.2 to 1.0wt% of Mn, less than or equal to 0.01wt% of P, less than or equal to 0.006wt% of S, 0.2 to 0.5wt% of Cu, 2.5 to 7.0wt% of Cr, 0.2 to 1.2wt% of Ni, 0.02 to 0.06wt% of Nb, 0.01 to 0.05wt% of Al, less than or equal to 0.05wt% of N, 0.01 to 0.10wt% of Ti and the balance of Fe and the unavoidable impurities. The steel plate made of the steel has the yield strength more than 550MPa and excellent toughness, and the relative corrosion rate is simultaneously reduced by one time on the basis of the traditional weathering steel so as to satisfy the requirement of enhancing the corrosion resistance of the steel for railway vehicles and reach the purposes of prolonging the service duration and reducing the maintenance cost.

Description

technical field [0001] The invention belongs to the field of low-alloy steel manufacture, and relates to a high-corrosion-resistant Cr-containing weather-resistant steel with a yield strength of 550 MPa and excellent toughness and a manufacturing method thereof. Background technique [0002] Weathering steel, or atmospheric corrosion resistant steel. Under atmospheric service conditions, the alloy elements in the steel interact with each other, and a dense rust layer with α-FeOOH as the main component is formed on the surface, which is thermodynamically stable and does not participate in the cathodic reduction process of steel electrochemical corrosion. The enrichment of copper, chromium and other elements in the rust layer makes the rust layer have ion-selective permeation characteristics, thereby significantly improving the atmospheric corrosion resistance of weathering steel. Due to its high corrosion resistance, weathering steel is widely used in railway vehicle manufac...

AI Technical Summary

Problems solved by technology

The addition of these elements, on the one hand, increases the manufacturing cost and difficulty, on the other hand, it is unfavorable to the welding and toughness of the steel plate

[0005] It can be seen that the weathering steel in the prior art can not fully meet the current use and manufacturing requirements, and it is necessary to develop a weathering steel with high corrosion resistance, high strength and economical production

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