Technology method for using thin slab for continuous casting and rolling to produce low-carbon high-niobium high-strength toughness steel belt

Abstract

The invention belongs to the preparing field of continuous casting and rolling of an abbreviated bar strip, in particular to the technique which utilizes continuous casting and rolling of the bar strip to produce a steel strip of low-carbon, high-niobium and high-obdurability. The specific procedures includes that the soaking temperature of a casting blank is controlled between 1100-118 DEG C in the process of continuous casting and rolling of an abbreviated bar strip, the open rolling temperature is <=1050 DEG C, the deformations is between 40%-50%, the final rolling temperature is between 800-900 DEG C, and the coiling temperature is between 500-65 DEG C. In the process of continuous casting and rolling of an abbreviated bar strip, 5-7 suites of racks are hot-rolled, the relative draft is F1-F2:40-50%, F3-F4:20-40%, F5-F7:5-30%. Controlled cooling is adopted to achieve quick controlled cooling to further reach the coiling temperature after the final rolling, and rate of cooling is more than 10 DEG C / s. Compared to the present techniques, the invention has the advantages that cost is low, technique is simple, polymorphy is simultaneously eliminated, and the final steel strip structure is even and thin, thereby the mechanic performance is fine.

Description

technical field [0001] The invention belongs to the field of continuous casting and rolling of thin slabs, in particular to a process for producing low-carbon, high-niobium, high-strength and toughness steel strips by continuous casting and rolling of thin slabs, and is mainly used in petrochemical, transportation equipment, engineering machinery and other industries. Preparation of high-strength toughness steel strip. Background technique [0002] In the prior art, niobium is one of the most significant microalloying elements for inhibiting austenite recrystallization, and is the most mature microalloying element in hot strip production. The mechanism of action is to flatten the deformed austenite, increase the dislocation density and distribution of deformation bands, increase the effective grain boundary area of ​​γ-α phase transformation, and through the dragging effect of solid solution niobium and the microscopic precipitation induced by deformation. Alloy carbonitrid...

AI Technical Summary

Problems solved by technology

However, one of the main problems in the production of niobium-containing steel strips by thin slab continuous casting and rolling is that mixed crystals are prone to occur. Uniformity, which in turn leads to deterioration of the mechanical properties of the finished strip

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