A short-process method for producing high-strength thin strip steel

Abstract

A method for producing high-strength thin strip steel in a short process comprises the first step of carrying out smelting and casting, wherein a twin roll strip casting technology is adopted, the second step of carrying out online hot rolling, the third step of carrying out cooling, wherein atomization cooling is adopted, the atomized cooled water mist is directly sprayed on the surface of the strip steel, the fourth step of carrying out scale breaking and blowing for sweeping, the fifth step of carrying out anti-oxidation intensive cooling and scale removing, wherein gas along with dry ice is directly sprayed on the surface of the strip steel for scale removing and intensive cooling, the sixth step of carrying out jet flow for scale removing, wherein solid-liquid mixed media are sprayed to the surface of the strip steel at a high speed, and the seventh step of carrying out straightening and reeling up. According to the method, the twin roll strip casting technology is utilized for producing the thin high-strength strip steel containing copper, hot rolling is performed on the casting belt, and then staged intensive cooling, oxide skin controlling and acid-free scale removing are combined and performed on the casting belt, so that the length of a production line is further shortened, and productivity is enhanced; meanwhile, the strength of the strip steel is increased through intensive cooling, the malleability of the strip steel is improved through grain refinement, and pollution to the environment is reduced by the adoption of the acid-free scale removing method.

Description

technical field [0001] The invention relates to a continuous casting process, in particular to a short-flow method for producing high-strength thin strip steel. Background technique [0002] Traditional thin strips are mostly produced by multi-pass continuous rolling of cast slabs with a thickness of 70-200mm, while cast strips produced by twin-roll thin strip continuous casting process are rolled into hot strips in one or two passes. The rolled strip can be put into the market after dephosphorization treatment. Compared with the traditional strip production process, the former has a shorter production line and requires less energy. It is a low-carbon and environmentally friendly hot-rolled thin strip production process. [0003] The typical process flow of twin-roll thin strip continuous casting is as follows: figure 1 As shown, the molten steel in the ladle 1 is poured directly through the nozzle 2, the tundish 3 and the flow distributor 4 in a room surrounded by two rel...

AI Technical Summary

Problems solved by technology

However, how to control the thickness of the scale during the conveying process from the rolling mill to the coil is seldom covered by relevant patents, especially in the process of cooling the strip by laminar flow cooling or spray cooling, the high temperature strip is in contact with the cooling water , the thickness of the scale on the surface of the cast strip increases rapidly; at the same time, the contact between the high-temperature strip steel and the cooling water will cause many problems: first, water spots (rust spots) will be formed on the surface of the cast strip, which will affect the surface quality; The cooling water used for laminar cooling or spray cooling is likely to cause uneven local cooling on the surface of the strip, resulting in uneven microstructure inside the strip, resulting in uneven performance of the strip and affecting product quality; third, strip steel Partial cooling on the surface is not uniform, which will cause the deterioration of the shape of the plate and affect the quality of the shape of the plate

In addition, laminar flow cooling or spray cooling is used, the cooling rate is limited, and it is difficult to produce high-strength steel with a yield strength of 550MPa or more

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