A kind of q460 grade fire-resistant and weather-resistant steel and its preparation method

Abstract

The invention discloses a Q460-grade fire-resistant weathering steel which comprises the following chemical components in percentage by weight: 0.01-0.20% of C, 0.1-0.4% of Si, 0.5-1.5% of Mn, 0.1-1.0% of Cr, at most 1.0% of Ni, at most 1.0% of Cu, 0.01-0.05% of Nb, 0.01-0.05% of Ti, at most 0.015% of P, at most 0.0020% of S, and the balance of Fe and inevitable impurities, wherein the total amount of the impurity elements does not exceed 0.05%. The steel is subjected to smelting and two-stage rolling, so the prepared steel has excellent fire resistance and weather resistance. The method cancels the component of the precious metal Mo, and enhances the grade of the finished steel.

Description

technical field [0001] The invention relates to a fire-resistant and weather-resistant steel and a preparation method thereof, in particular to a Q460 grade fire-resistant and weather-resistant steel and a preparation method thereof, belonging to the technical field of low-alloy corrosion-resistant medium-thick plate rolling. Background technique [0002] When the temperature of ordinary construction steel reaches 400°C, the yield strength will drop to half of the strength at room temperature, and when the temperature reaches 600°C, the strength will basically be lost. In order to prevent fire damage to steel structure buildings, it is necessary to spray a fireproof layer for protection. Spraying refractory materials doubles the cost of the building, prolongs the construction period, reduces the effective indoor area, and the splash of spraying operations pollutes the environment. Therefore, one of the development trends of modern buildings is to reduce fire-resistant coati...

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Problems solved by technology

[0009] It can be seen that the refractory steels of the above patents all use Mo as a high-temperature strengthening element in the composition design, the addition of precious alloys is relatively large, and some steel grades are low or the manufacturing cost is high, which limits market promotion and application. A Q460 grade smart Type fire-resistant and weather-resistant steel and its manufacturing method are: the innovative application of nano-precipitation technology, the composition design uses Cu as the main high-temperature strengthening element, and uses ε-Cu to precipitate and strengthen during the heating process to improve the high-temperature yield strength; at the same time, Cu can make the material have Good weather resistance; the production process is TMCP, which has the characteristics of short production process, high production efficiency and earthquake resistance

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