Hot rolled steel coil is a demanded material in the construction industry, architecture, automotive, machine tool building, decoration, etc. It is used not only as an intermediate raw material, but also as an independent building material. The demand for hot-rolled strip has multiplied on the market. Therefore, to maintain competitiveness in the market, new and existing rolling mills should be carried out the most effective activities. Getting hot rolled strip is the basis of steel production. Since hot rolling is used in the production of almost half of steel products, the highest requirements are placed on the performance and working hours of hot rolling mills, besides, it is important to ensure the accuracy of geometric indicators and the achievement of optimal physicochemical properties of the rolled products.
APPLICATION OF HOT-ROLLED COIL
Steel roll with a thickness of 4 – 8 mm can be used for the manufacture of reinforcement, intended for the reinforcement of concrete structures and products. The material with a thickness of 2-4 mm is used for the production of hot-rolled greasy strips, of which a different grid, corners that are an auxiliary material in the manufacture of corrugated boarding, metal siding, wall and roof sandwich panels are made.
PRODUCTION OF THE HOT ROLLED COIL
The manufacture of hot rolled coils involves the use of steel of two different types – ordinary of general purpose and high-quality carbon. Accordingly: low-alloyed and high-alloyed. Production of this material is carried out on sheet rolling mills using the hot rolling method with further winding into a roll, observing all state standards. An important characteristic of a hot rolled coil is the rolling accuracy that is divided into two categories: increased (A), normal (B).
The new inventions in the production of hot rolled coil are intended to provide the required level of mechanical properties and surface quality of hot-rolled steel in the production of wide hot rolled strips. The invention relates to rolling production and can be used in the production of wide hot-rolled strips mainly pipe steel grades. The method includes heating the slab for hot rolling, rolling it in the rough and finishing continuous groups of stands of the broadband mill, differentiated cooling of the strip with water from the top and bottom with sections of the dividing device in the interstand gaps of the finishing group of the mill and on the outlet roller table with subsequent rolling of the strip into a roll. The formation of products with high strength, plastic properties, without the formation of transverse cracks in the deformation process is ensured by the fact that the set temperature of the end of rolling for strips with a thickness of 16.1 mm to 17mm is 770-810 ° С, for strips of more than 17, 1 mm to 18.7 mm – 750-790 ° C.
A disadvantage of the known methods in the production of hot rolled coil is the difficulty of providing the required level of mechanical properties of hot-rolled strips and surface quality with maximum performance of a wide-strip hot rolling mill, especially when producing thick strips of 16 mm or more thickness.