Calculation of Spread, Elongation, Effective Roll Radius, Roll Force and Torque When Rolling in the Square-Diamond, Square-Oval and Round-Oval Passes

Abstract

By means of laboratory hot rolling test of mild steel bars, those chracteristic values of the pass rollings shown in the title were measured under the wide range of rolling conditions.
Through the treatment of experimental data, it has been found for each pass sequence that 1) the spread exponent (k) defined to determine spread and elogation of metals may be expressed as a function of shape factor (US), and 2) mean forward slip (φ) defined to determine the effective roll radius may be expressed as a function of elongation (λ-1), and 3) non dimensional roll force (Q) and torque arm coefficient (φ) may be expressed as functions of mean roll gap ratio (m).
Making use of these empirical expressions, a new calculation mass-model was presented, which enabled to predict those characteristic values of rolling with very high accuracy for any arbitrary rolling conditions of those pass sequences.