An in-line model for predicting front end bending in hot plate rolling and its experimental verification

Abstract

In this article, we present an in-line model that can be used for predicting the front end bending of a material frequently produced by hot plate rolling under asymmetric rolling conditions. The in-line model was formulated by examining the relationship between asymmetric rolling conditions and front end bending slope and by expressing front end bending slope as a function of asymmetric rolling conditions as well as roll-bite profiles (shape factor and reduction ratio). We also performed a pilot hot plate rolling test to verify the usefulness of the proposed in-line model. Before the rolling test began, a board-shaped specimen that had been heated in a reheating furnace at 1100 °C was half submerged, horizontally, in a bathtub filled with cold water to derive temperature variation of the specimen along the specimen’s thickness direction, which is one of the asymmetric rolling conditions that produce front end bending. Results show that front end bending slopes formulated as a double-linear function of asymmetric rolling conditions as well as roll-bite profiles (i.e. shape factor and reduction ratio) were successful. The proposed in-line model computed immediately the amount of front end bending whenever the roll-bite profiles and asymmetric rolling conditions changed during rolling. The results predicted by the in-line model were within 6.5%–10.3% of the front end bending slopes measured from the pilot hot plate rolling test.