Cold-rolled weathering resistant steel and preparation method thereof

Abstract

The invention discloses cold-rolled weathering resistant steel and a preparation method thereof. The cold-rolled weathering resistant steel comprises the following chemical components of, by weight, 0.05%-0.08% of C, 0.25%-0.40% of Si, 0.25%-0.40% of Mn, 0.060%-0.100% of P, less than or equal to 0.020% of S, 0.008%-0.030% of Als, 0.12%-0.20% of Ni, 0.25%-0.40% of Cu, 0.30%-0.50% of Cr, less than or equal to 0.0080% of N, and the balance Fe and inevitable impurities. Reasonable chemical component design is achieved, noble metal alloys such as Ti, Nb and B are not added, a hot rolling process, acold rolling process, a continuous annealing process and a flattening process are controlled, so that the cold-rolled weathering resistant steel with good surface quality is obtained, in the case ofthe cold-rolled weathering resistant steel, the yield strength is larger than or equal to 350 MPa, the tensile strength is larger than or equal to 500 MPa, the A50 elongation percentage is larger thanor equal to 30%, and the good atmospheric corrosion resistance and welding performance are achieved.

Description

technical field [0001] The invention belongs to the technical field of steel preparation, and in particular relates to a cold-rolled weathering steel and a preparation method thereof. Background technique [0002] Atmospheric corrosion-resistant steel plates, also known as weather-resistant steels, are widely used in industries such as railway carriages, highway guardrails, bridge structural steel, and ship containers. The weather-resistant steel plate not only needs to have certain corrosion resistance, but also needs higher strength and better welding performance. [0003] Due to the structural requirements, hot-rolled weather-resistant steel plates are widely used, but with the development of society, there are more and more demands for cold-rolled weather-resistant steel plates. The current weather-resistant steel plates mainly rely on the addition of a large amount of Mn, Si, Cu, Cr, Ni, etc. elements to ensure weather resistance, and the addition of these elements can...

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Problems solved by technology

[0003] Due to the structural requirements, hot-rolled weather-resistant steel plates are widely used, but with the development of society, there are more and more demands for cold-rolled weather-resistant steel plates. The current weather-resistant steel plates mainly rely on the addition of a large amount of Mn, Si, Cu, Cr, Ni, etc. elements to ensure weather resistance, and the addition of these elements can improve the strength of cold-rolled weather-resistant steel sheets, but the increase of alloy elements will inevitably affect the reduction of weldability, abnormal structure, etc., and the production process is difficult to control. Therefore, it is necessary to add Ti, Precious elements such as Nb, B, and V are used to improve the structure and properties of the steel plate, so the increase of alloy elements will inevitably lead to an increase in the cost of cold-rolled steel plates

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