Measurement and prediction of the centering effect of a profiled roll on steel strips

Abstract

In a steel continuous processing line, the strip passes over an important number of rolls and strip walking can occur due to strip defects, roll profile or roll misalignment. Since decades, two solutions are used in order to keep a strip centered in the line : deflection rolls are profiled (with crowned or tapered shapes) and steering rolls are implemented, in different part of the lines.

As in other industries, the constant challenge for a line manager in the steel industry is to increase the productivity of the line and to adapt the lines to new products.

To achieve these goals on pickling lines or continuous annealing lines, it is necessary in some cases to know precisely about the centering effect of profiled rolls on the strip. This data can be used either to improve the strip centering by increasing the roll profile or to avoid other defects as wrinkles, by reducing the crown without increasing strip walking.

In order to quantify the centering efficiency of a roll, Irsid and Sollac developed a theoretical model for calculating the strip position after a profiled roll and compared it to experimental data measured on two pilot lines.