Comparative Analysis of the Durability of Solid-Forged and Bimetallic Backup Rolls on Rolling Mills

A method has been developed for evaluating the durability of large solid-forged and bimetallic backup rolls on rolling mills with allowance for the residual stresses from heat treatment. Results are presented from a numerical study performed for a 600/1350 × 1420 four-high mill. The stresses created in the rolling operation are determined by solving a three-dimensional contact problem in the finite-element program ANSYS. The service life of the rolls is determined by calculating their durability in a deterministic formulation. The calculation is performed with the use of the Paris equation to describe the linear section of the kinetic diagram that characterizes fatigue fracture. It is shown that hard-faced bimetallic rolls subjected to carbide-intermetallide hardening last roughly twice as long as solid-forged rolls made of traditional low-alloy roll steels.