### The Calibration

Theory and practice of the rolling process have developed certain rules of placing the gauge in the rolls, to ensure optimal operating conditions of rolls and maximum performance rolling mill. These rules and the choice of the calibration circuits are the subject of sizing rolls. Thus, when calculating the calibration rolls value drawing the aisles must be taken together with the definition of successive shapes and sizes caliber, providing the reception quality of steel and the exact dimensions of the profile. It should also consider the possibility of creating an environment that would ensure maximum performance of the camp, the minimum energy expenditure and consumption of rolling tool. A very important element calibration rolls is a rational distribution of gauge on rollers, allows you to roll assortment of camp with minimal time for handling rolls and change calibers, the use of gauges and preparatory drafts stands no one profile for a group rolled products. The most optimal solution of all issues in obtaining this type of rolled (the required size profile, mechanical properties, surface condition, etc.) can be carried out only in full consideration of the features of the rolling mill.

However, many factors that should be taken into account when sizing rolls, and no established exact relationships allow to solve this engineering problem only by repeated approximations. Gauges used in rolling is subdivided into the following groups according to their purpose: – crimping, or exhaust, gauges used to reduce cross-sectional area of the ingot or billet. Exhaust gauges are the drawer, the square with a diagonal, rhombic, oval. Some combination of these calibers forms a system of calibers, such as a diamond – a diamond, the diamond – square, square – oval, etc. – drafts, or preparations, gauges, which along with a further decrease in cross-section profile of the strip is processed with a gradual approximation of its size and shape to the final section – predotdelochnye or predchistovye gauges prior to finishing – finishing, or Chistov, gauges, giving final shape to the profile section. The sizes of these calibers almost coincide with the transverse dimensions of the finished profile, the difference in 1,2-1,5% of the big party given for shrinkage during cooling. By way of crashing into the roller gauges are divided into the open when the line connector roll falls within the caliber, and closed, at which the line connector is located outside the fire.