Factors influencing rolling mechanics

Rolling is the most extensively used steel metal forming process, It provides high production and close control of the final product.

Rolling mill for steel

The main factors which influence the mechanics of rolling are as follows.

The diameter of the rollsAmount of reduction in one passThe initial thickness of the material to be rolledThe speed of rolling which decides the strain rateThe front and back tensionsThe nature of friction between the rolls and the steel being rolledThe temperature range of the steel material and the rollsThe physical properties of the steel material being rolledThe shape of the roll contour of roll pass in which the steel material being deformedThe mill behaviour under loadThe effect of previous treatment of the material resulting in work hardening or other effectsThe elastic deformation of rolls under loadThe deformation resistance of the metal as influenced by metallurgy, temperature and strain rate.The state of anisotropy of the materialThe aspect ratio, or the ratio of the width of the rolling stock to the initial thickness


The above parameters may singly or jointly, in combinations of two or more, generate secondary parameters and phenomena more directly related to and commonly associated with the rolling process. Roll pressure, torque, work and power are influenced by these factors. Major of these parameters are given below.

Coefficient of draught, absolute draught and relative draught, which are established by the initial draught, which are established by the initial and final mean thicknesses of the rolling stock.Slip which is characterized by the difference of the linear speed of the rolling stock and the peripheral speed of the rolls. Neutral angle is determined by the point of no slip.

Spread is the difference in width of the exit material as compared to the ingoing rolling stock.

Coefficient of elongation is dependent on the relative values of the draught and spread.

Roll bite which is a function of draught, roll diameter, coefficient of friction and ingoing thickness.