Analytical Model for the Wide-Strip Rolling Mills Working Rolls Wear-Out Failures

Abstract

The paper proposes a mathematical model for the gradual shape deterioration of wide-strip rolling mills working rolls active generatrixes subject to wear within the working zone during tandem rolling strips of a specified gauge. While modeling, the authors have determined the theoretical dependency needed to estimate the mean life of working rolls according to the transverse strip gauge interference criterion. Gauge interference of tandem-rolled strip transverse section shall be derived from the sum of the values of current shape of upper and lower working rolls active generatrixes, which are calculated based on strip width. In its turn, an active section of each roll shall be calculated for every following strip as a difference between the current roll radius values at the crown middle and that above/below the strip edge, while the shape deterioration rate of active roll generatrixes shall be defined by the difference between the roll wear rates in these sections. To estimate the rate of roll wear during rolling every following strip of the specified gauge, the base dependency of the structure-energy concept describing wear of stationary tribocouplings is used, which has been obtained by simultaneous solution of fundamental equations of molecule-mechanical and structure-energy friction theories. The moment of working roll failure (expected life) is determined based on the condition of achieving the nominal limit by gauge interference of a current strip.