High-corrosion-resistance steel and manufacturing method thereof

Abstract

The invention discloses high-corrosion-resistance steel and a manufacturing method thereof. The high-corrosion-resistance steel is prepared from the chemical components in percentage by weight: 0.02-0.06% of C, 0.1-0.5% of Si, 0.4-1.7% of Mn, less than or equal to 0.02 % of P, 4.0-6.0% of Cr, 1.0-3.0% of Ni, less than or equal to 0.007% of S, 0.004-0.010 % of N, less than 0.001% of Als, 0.001-0.006% of B, greater than 250 of Mn/S, 0.007-0.020% of total oxygen [O]<T>, and the balance of Fe and inevitable impurities. Alloying elements such as Cr and Ni and an element B are selectively added intoplain carbon steel; the alkalinity of slag, the type and melting point of inclusions in steel, the content of free oxygen in molten steel and the content of acid-soluble aluminum Als are controlled in the smelting process; double-roller thin strip continuous casting is adopted for casting a cast strip, the cast strip directly enters a lower closed chamber with a non-oxidizing atmosphere and enters an online rolling mill for hot rolling under a closed condition, and strip steel is cooled in a gas atomization cooling mode after rolling.

Description

technical field [0001] The invention belongs to the continuous casting process, and in particular relates to a high corrosion-resistant steel and a manufacturing method thereof. 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, and it is u...

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 sl

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