Inverse estimation of transient temperature distribution in the end quenching test

End quenching is a simple test applied to engineering materials to determin e their mechanical characteristics under normal heat treatment. The work re ported here is part of a large programme aimed at the prediction of the the rmal stress and strain generated during the quenching of low-alloy steel co mponents. It is very difficult to obtain the temperature history or cooling rate on the surface of the specimen under quenching. The estimation scheme of the temperature history proposed here was used to generate the relation ship of the cooling rate with the mechanical properties of the materials fo r most thermal processes. The aim of this work is to calculate the heat flu x and temperature distribution of the quenching surface, where the temperat ures are not easy to measure during quenching. This study proposed an inver se prediction scheme with the finite-element method. The interior temperatu re near to the quenching surface was measured by a thermocouple and provide d the input data for the inverse estimation of the unknown thermal boundari es in the heat-conduction problem of the quenching specimen. An accurate es timation of the heat dissipation of the quenching surface has been achieved . Here the conjugate gradient method is used to improve the estimation of t he distribution of the surface temperature and heat flux for a 2D cylindric al co-ordinate problem. (C) 1999 Published by Elsevier Science S.A. All rig hts reserved.