A Numerical Method for Estimating the Temperature Distributions in Extrusion Through Conical Dies

Abstract

A numerical method was developed to predict the local temperatures in the billet and in the tooling before the extrusion starts. The method was further extended for calculating the nonsteady-state temperature distributions during extrusion. The necessary velocity, strain rate, and strain fields were obtained from a visioplaslicity experiment. Heat generation and conduction were approximated in two consecutive steps taking place during equal time increments Δt. The temperature dependencies of the flow stress and of the thermal constants of the billet and the tool materials were taken into account, and the entire procedure was programmed in FORTRAN IV to facilitate its general use for analyzing extrusions with different extrusion ratios, materials, die angles, ram speeds, and friction conditions.