High Temperature Stress-Strain Properties of a Low-Carbon Steel from Hot Machining Tests

Abstract

Machining tests are described in which the cutting speed is kept constant and the primary shear zone temperature varied through a wide range by preheating the workpiece. Variations of the constants σ1 and n of the assumed stress-strain equation σ = σ1 εnwith temperature, for an estimated strain rate of 900/s, are obtained. These show a range of temperature in which dynamic strain ageing takes place. This is consistent with results of conventional machining tests on the same material in which dynamic strain ageing takes place in the secondary zone in a certain speed range.Implications of the results for the machining process are discussed and explanations suggested for variation of force with speed in conventional machining and force with temperature in hot machining.