A method for producing high-strength and high-corrosion-resistant steel by thin strip continuous casting

Abstract

A method for thin strip continuous casting to produce high-strength and high-corrosion-resistant steel, which includes the following steps: a) smelting, smelting according to the following chemical composition, and its chemical composition weight percentage is: C 0.02-0.06%, Si 0.1-0.5%, Mn 0.4‑1.7%, P≤0.02%, Cr 4.0‑6.0%, Ni 1.0‑3.0%, S≤0.007%, N: 0.004‑0.010%, Als<0.001%, total oxygen [O] T : 0.007‑0.020%, remaining Fe and unavoidable impurities, and, at the same time, satisfying: one or two elements in Nb: 0.01‑0.08% or V: 0.01‑0.08%; Mn / S>250; b) even Casting, double-roll thin strip continuous casting to obtain the cast strip; c) lower airtight protection, the cast belt directly enters the lower airtight chamber after leaving the crystallization roller, and the lower airtight chamber passes non-oxidizing gas; d) online hot rolling, the cast belt is sealed in the lower airtight chamber The room is sent to the rolling mill through pinch rollers, and rolled into strip steel; e) the strip steel is cooled by gas atomization cooling; f) the strip steel is coiled.

Description

Technical field [0001] The present invention relates to a continuous casting process, and more particularly to a method of producing high-strength high-resistance steel production in thinband continuous casting. Background technique [0002] The traditional thin belt steel is mostly produced by a plurality of consecutive rolling by a slab for 70-200 mm. Traditional hot rolling process is: continuous casting + slabs to heat insulation + thick rolling + finishing + cooling + Volume, that is, the thickness of the thickness of 200 mm is first obtained by continuous casting, and then the slab is reheated and thermally, and the thickness is performed, the thickness is generally greater than 2 mm steel strip, and finally carry the steel strip Lamination cooling and winding, complete the entire hot rolling production process. If the thickness is less than 1.5 mm (inclusive), the difficulty is relatively large, and the hot-rolled steel strip is often necessary to perform subsequent cold r...

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, and the present invention requires that the traditional corrosion-resistant steel be doubled

[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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