Evaluation of heat transfer coefficient during heat treatment by inverse analysis

Reliable prediction of the properties of a heat-treated workpiece requires accurate data of the heat transfer coefficient during heat treatment process. In the present investigation, inverse heat transfer formulation using a two-dimensional finite element method was developed as a tool to evaluate heat transfer coefficient during heat treatment. The formulation has a function of providing a time profile of heat transfer coefficient on various surface locations with measured temperature at proper locations within workpiece under heat treatment. By the present formulation, heat transfer coefficients were evaluated for fan and water cooling of heated solid cylindrical carbon steel specimens. Comparison of the obtained heat transfer coefficients against the existing results on heat treatment shows that the obtained values of coefficients have reasonable accuracy, enough to predict the properties of the heat-treated workpiece.