Control and modifying unit of scale of hot rolling strip steel

Abstract

The invention discloses a control and modifying unit of scale of hot rolling strip steel, comprising an uncoiling mechanism, a spraying and drying device, a withdrawing-straightening device, a heating device, a cooling device, a secondary drying device, a surface passivating and oil-coating device, a winding and pinch roll and a winding machine which are connected in sequence by roller ways, wherein a blowing device is arranged between the withdrawing-straightening device and the heating device; and the winding machine is provided with an edge anti-oxidation spraying device and a weakly-alkaline neutralizer spraying device. The control and modifying unit provided by the invention has the advantages that according to different requirements on the scale structures on the surface of the strip steel, the offline strip steel is unwound again by the unwinding mechanism, the temperature of the strip steel is controlled by the heating device, the cooling rate and the cooling temperature of the strip steel are controlled by the cooling device, and then the needed scale structures which are free from acid cleaning and easy for acid cleaning are obtained; in the scale structure which is free from acid cleaning, the content of Fe3O4 is up to more than 80%, in the scale structure which is easy for acid cleaning, the content of FeO can be up to more than 50%, and the scale structures are superior to the scale structure obtained by the traditional scale control process.

Description

technical field [0001] The invention relates to the field of hot-rolled strip steel production, in particular to a hot-rolled strip steel oxide scale control and modification unit. Background technique [0002] At present, the domestic steel market competition is becoming increasingly fierce, product homogeneity is serious, and users' requirements for hot-rolled strip products are becoming more and more stringent. Users have higher requirements on product size, shape accuracy, mechanical properties, etc. With the development of modern industry and the trend of "replacing cooling with heat" in the iron and steel industry, users have higher requirements on the surface quality of hot-rolled strip products. For example, based on the consideration of cost reduction and efficiency increase, energy saving and environmental protection, users have certain requirements on the performance of the iron oxide scale on the surface of hot-rolled strip products, such as the difficulty of pic...

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Problems solved by technology

The cooling rate of the above two forced cooling methods is greatly improved compared with fan blowing cooling, but the above methods are to cool the steel coil in the form of coils. When the hot-rolled steel coils are cooled in coils, due to the cooling conditions of different parts of the steel coils Oxygen supply is different, and the condition of the oxide scale at the wide side and the middle part of the plate is usually not completely consistent, resulting in uneven distribution of the oxide scale in the width direction of the strip, which adversely affects the uniformity of its performance, especially during pickling. It is easy to cause uneven pickling, resulting in over pickling

[0006] In addition, hot-rolled finished coils are susceptible to atmospheric corrosion and local electrochemical crevice corrosion caused by rain and condensation during storage and transportation, which will cause rust or severe "pitting" corrosion on the surface of the hot-rolled steel plate, and the surface of the strip is also prone to corrosion. In a humid environment, acidic interfacial reactions occur with bundled materials such as straw mats and straw ropes, resulting in deterioration of the surface. Pickling-free steel coils are directly formed without shot blasting, sandblasting, pickling and other processes, and users do not need to It is allowed to rust on the surface, so it is necessary to do anti-rust and acid-base neutralization treatment on the surface when producing pickling-free steel

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