Fine-grain hot-rolled steel plate and strip and preparation method thereof

Abstract

The invention discloses a fine-grain hot-rolled steel plate and strip and a preparation method thereof, and belongs to the field of steel production. The fine-grain hot-rolled steel plate and strip comprises the following components: 0.03% to 0.35 % of C, 0.05% to 0.8 % of Si, 0.5% to 2.5 % of Mn, 0.001% to 0.035 % of P, 0.001% to 0.035 % of S, 0.001% to 0.07 % of Al, 0.002% to 0.05 % of Ti, 0.0006% to 0.03 % of fine grain element, 0.001% to 0.012 % of O, 0.002% to 0.015 % of N and the balance Fe and inevitable impurities. The fine grain element is one or more of B, Mg, Zr and Ca. The contained inclusions in the fine-grain hot-rolled steel plate and strip are Al2O3 inclusion, TiOx inclusion, TiN inclusion, AlN inclusion, MnS inclusion, and the inclusions formed by fine grain elements. The preparation method comprises the steps of smelting, refining, continuous casting, hot rolling and cooling, according to the method, components and inclusions of the hot-rolled steel plate and strip are optimally designed, smelting and rolling process improvement is combined, so that grain size refinement under the high-temperature rolling condition is achieved, and then the strength and toughness of the steel are improved.

Description

technical field [0001] The invention belongs to the technical field of iron and steel production, and in particular relates to a fine-grained hot-rolled strip steel and a preparation method thereof. Background technique [0002] Low-alloy high-strength hot-rolled strip steel is widely used in economic and social construction. With the continuous improvement of industrial production technology, the production and application of hot-rolled strip steel is developing in the direction of high strength and toughness, low alloy cost and high production efficiency. There are many ways to improve the strength of the steel plate, but grain refinement can improve the strength and toughness at the same time, and save the amount of alloy addition, so it is widely used in the steel industry. [0003] At present, the process of microalloying plus controlled rolling and controlled cooling is generally used in hot-rolled strip steel to achieve the purpose of refining the structure and improv...

AI Technical Summary

Problems solved by technology

[0016] The above-mentioned existing technologies can obtain fine-grained structures to meet the performance requirements after increasing the rolling temperature, but all adopt the method of alloying or ultra-fast cooling immediately after rolling, which brings pressure on production costs and technical implementation

However, there is no relevant existing technology that can be adopted to achieve this purpose, and further in-depth research is needed

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