Method for producing high-corrosion-resistance steel through twin-roll thin-strip continuous casting

Abstract

The invention discloses a method for producing high-corrosion-resistance steel through twin-roll thin-strip continuous casting. The method comprises the following steps of (a) smelting: carrying out smelting according to the following chemical components in percentage by weight, 0.02-0.06% of C, 0.1-0.5% of Si, 0.4-1.7% of Mn, smaller than or equal to 0.02% of P, 4.0-6.0% of Cr, 1.0-3.0% of Ni, smaller than or equal to 0.007% of S, 0.004-0.010% of N, smaller than 0.001% of Als, greater than 250 of Mn / S, 0.007-0.020% of total oxygen [O]T and the balance of Fe and inevitable impurities; (b) continuous casting: adopting a twin-roll thin-strip continuous casting process; c) protecting in a lower closed chamber; d) online hot rolling; e) cooling after rolling: cooling the rolled strip steel ina gas atomization cooling manner; and f) strip steel coiling: directly coiling the cooled hot-rolled strip steel into a coil after the end with poor quality of the cooled hot-rolled strip steel is cutoff by an end shear, and controlling the coiling temperature of the hot-rolled strip to be 600-700 DEG C.

Description

technical field [0001] The invention relates to a continuous casting process, in particular to a method for producing high corrosion-resistant steel by twin-roll strip continuous casting. Background technique [0002] Most of the traditional thin strip steel is produced by multi-pass continuous rolling of the slab with a thickness of 70-200mm. The traditional hot rolling process is: continuous casting + slab reheating and heat preservation + rough rolling + finishing rolling + cooling + Coiling, that is, firstly obtain a cast slab with a thickness of about 200mm through continuous casting, reheat the cast slab and keep it warm, then perform rough rolling and finish rolling to obtain a steel strip with a thickness generally greater than 2mm, and finally process the steel strip Laminar cooling and coiling complete the whole hot rolling production process. If it is necessary to produce a steel strip with a thickness of less than 1.5mm (inclusive), it is relatively difficult, a...

AI Technical Summary

Problems solved by technology

At the same time, the contact of high-temperature strip steel with cooling water will cause many problems: first, water spots (rust spots) will be formed on the surface of the strip steel, which will affect the surface quality; second, the cooling water used for laminar flow cooling or spray cooling It is easy to cause uneven local cooling on the surface of the strip, resulting in uneven microstructure inside the strip, resulting in uneven properties of the strip and affecting product quality; third, uneven local cooling on the surface of the strip will cause deterioration of the shape of the strip , affecting the shape quality

[0017] (1) Long process flow, high energy consumption, many units and equipment, and high infrastructure costs lead to high production costs

[0018] (2) Corrosion-resistant steel contains a relatively high content of copper and other segregation-prone elements that improve the corrosion resistance of the steel strip. The traditional process is prone to macro-segregation of copper and other elements due to the slow solidification and cooling of the slab, resulting in various segregation of the slab. Anisotropy and macro cracks appear, and the yield is low

As a result, the corrosion resistance of the steel strip is not high

[0020] (4) The corrosion resistance of these corrosion-resistant steels cannot achieve the corrosion resistance requirements of the steel of the present invention, that is, it is doubled on the basis of traditional corrosion-resistant steels

[0021] (5) In the traditional process, since the microalloying elements cannot be maintained as a solid solution during the hot rolling process, partial precipitation occurs, resulting in fine grains of the steel structure, increased yield ratio, and poor formability, which will significantly increase the rolling load. Increase energy consumption and roll consumption, and cause greater damage to equipment, thus limiting the economical and practical production of high-strength corrosion-resistant steel hot-rolled products. Thickness range, usually ≤ 2mm

This not only increases the investment cost, but also significantly increases the floor area of ​​the thin strip continuous casting and rolling production line, reducing the advantages of the production line

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