Refractory steel and manufacturing method thereof

Abstract

The invention provides a fire resistant steel and process for preparing it, wherein C, Si, Mn, Cr and Mo are used as the primary alloy elements for the steel with added trace elements of Cu, Nb, V, Ni, Ti, Al, B and RE, wherein controlled rolling and controlled chilling processes are used, and by controlling carbon equivalent, alloy content and yield ratio, high-performance fire resistant steel with air corrosion resistance can be realized.

Description

technical field [0001] The invention belongs to the field of metal materials, in particular to refractory low-alloy steel for construction and a manufacturing method thereof. Background technique [0002] Fire-resistant steel for construction is a kind of low-alloy steel with fire-resistant properties developed in recent years. It plays a decisive role in building structural buildings with their own fire-preventing effects. According to new searches, the fire-resistant steels currently developed internationally, such as the Japanese patent "Fireproof Weldable Weathering Steel" with the patent No. It reaches 600°C within 1-3 hours, and the yield strength drops no less than 2 / 3 of its normal temperature, and even reaches 700°C, and within 1-3 hours, the yield strength drops no less than 2 / 3 of its normal temperature, but its resistance to 600°C High-temperature refractory steel does not control the production process and yield ratio, has high alloy content, is expensive, and ...

AI Technical Summary

Problems solved by technology

According to new searches, the fire-resistant steels currently developed internationally, such as the Japanese patent "Fireproof Weldable Weathering Steel" with the patent No. It reaches 600°C within 1-3 hours, and the yield strength drops no less than 2 / 3 of its normal temperature, and even reaches 700°C, and within 1-3 hours, the yield strength drops no less than 2 / 3 of its normal temperature, but its resistance to 600°C High temperature refractory steel does not control the production process and yield ratio, the alloy content is high, the cost is expensive, and it is not easy to weld

Although the production process of fire-resistant steel resistant to 700°C is controlled, the carbon equivalent and yield ratio are not controlled, so the cost is expensive, and it belongs to 58kg class fire-resistant steel, which is not suitable for the domestic construction steel market

[0003] Domestic construction steel generally adopts Q235 steel specified in GB700 and Q345 steel specified in GB / T1591. The disadvantage of this type of steel is that it softens when the temperature reaches 350°C and does not have fire resistance.

[0004] Wuhan Iron and Steel provides a fire-resistant steel with patent application number 011335629. Although the yield strength of this steel reaches 600°C within 1-3 hours, the drop is not less than 2 / 3 of its normal temperature, but there is also the problem of not controlling the carbon equivalent and yield strength ratio. disadvantages, and the alloy content is high, the price is expensive, and cannot meet the demand of the domestic structural steel market