Rolling mill: history and modern classification

Rolling mill as a device for processing metals and other materials by the pressure of several rotating rollers was first mentioned in the works of Leonardo da Vinci. The oldest mechanism, described by the great master in 1495, was intended for the processing of tin. Rolling devices were already widely used in the 17th century, where they worked on the basis of manual drives, which were later replaced by water (water wheel), and then on steam. Today, manual equipment is often used for handicraft work.

Rolling mill as a part of its equipment has the main part (a working stand, in which can be located from two to several rolls, electric motors and devices that transfer energy to the rolls from the engines) and auxiliary equipment (equipment for moving blanks, cutting, straightening, .). The design of the specific equipment is tied to the type of product that it produces.

Rolled products, depending on the type of cross-section, are divided into several groups, including:

- pipes (seamless or performed using welding);

- sheet metal (thin sheets or thick plates (more than 4 mm));

- long products (shaped or plain);

- special rolling (angular, C-shaped, with a variable profile, etc.).

Rolling mill by type of product can be assigned to one of the following groups: pipe-, tape-, hard-rolled, special, sheet, wire, strip, broadband, varietal, crimping (mainly blooming), billet, rail mill. Equipment of this kind is large-sized. For example, a small mill, considered to be small, can have a length of fifteen meters, and the largest one to this day is 5500 meters long (owned by Anshen Iron And The Steel Group).

The classification of rolling mills for structural features is as follows:

- single-pedestal (they include a cage, supplemented, for example, with six electric motors, five clutches, four reducers, three gear stands and two spindles);

- linear mills (the stands are located one after another, sometimes in several lines, the products are processed in one direction);

- consecutive (several odnokletievyh mills are located sequentially or in another order);

- continuous (the workpiece is processed simultaneously in a number of stands);

- semi-continuous (there are continuous sections and linear components of equipment).

How does the rolling mill work? First, the metal ingot is heated in special wells (about 1800 ° C), after which the electric car feeds it to the primary processing (for slabing or blooming), where bars are produced from the ingot. Further on, on other rolling equipment, metal sheets or finished products of a predetermined shape, such as a rail, etc., are produced. Modern equipment, as a rule, is a casting and rolling mill, which can process billets in cages at a speed of about 300 km per hour.

The manufacture of rolling mills is a complex and expensive process, nevertheless today in Russia there are enterprises that produce such products. In addition to the main and auxiliary equipment , high-precision automatics, lubricating equipment, as well as providing power plants with a total power of up to 200-300 megawatts are needed to successfully operate the complex.