A kind of high corrosion-resistant and weather-resistant steel and its manufacturing method

Abstract

The invention discloses a high corrosion-resistant and weather-resistant steel. The mass percentage ratio of chemical elements is: C: 0.03-0.05%, Si: 0.03-0.05%, Mn: 0.8-1.2%, Cu: 0.1-0.2%, Cr : 6.8‑8.2%, Ni: 0.05‑0.15%, Mo: 0.15‑0.25%, Al: 0.03‑0.05%, and the balance is Fe and other unavoidable impurities. In addition, the present invention also discloses a method for manufacturing the above-mentioned high corrosion-resistant and weather-resistant steel, which includes steps: (1) smelting and casting; (2) reheating: the billet is reheated to 1200°C-1260°C; ( 3) rough rolling; (4) finishing rolling; (5) coiling; (6) cooling to room temperature. The high corrosion-resistant and weather-resistant steel has high atmospheric corrosion resistance, and has high strength on the basis of retaining plasticity, low-temperature toughness and excellent formability.

Description

technical field [0001] The invention relates to a steel grade and a manufacturing method thereof, in particular to a weather-resistant steel and a manufacturing method thereof. Background technique [0002] Generally, the weather-resistant steel with a weather resistance index above 6.0 is called weather-resistant steel. Compared with ordinary carbon steel, weather-resistant steel has good atmospheric corrosion resistance and can effectively prolong the service life of steel structures, thereby reducing costs and pressure on the environment. The weather resistance index I is defined as: [0003] I=26.01Cu+3.88Ni+1.2Cr+1.49Si+17.28P-7.29CuNi-9.1NiP-33.39Cu 2 [0004] Under the atmospheric service environment of weathering steel, the alloying 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 electroc...

AI Technical Summary

Problems solved by technology

In the technical solution disclosed in this Chinese patent document, although the content of P element is not high, the addition of its corrosion-resistant alloy is not high, therefore, the weather-resistant index of the weather-resistant steel plate involved is still about 6.0, and the weather-resistant steel plate is resistant to atmospheric corrosion. The performance is equivalent to that of traditional weathering steel, but it cannot meet the requirements of unpainted use

[0008] In summary, it can be seen that the weathering index of weathering steel in the prior art is between 6.0 and 7.0, the atmospheric corrosion resistance is only comparable to that of traditional steels, and the yield strength is also low, which cannot meet the current requirements. Atmospheric corrosion resistance of weathering steel and demand for high strength and weight reduction

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