A network model to simulate transient non-lineal thermal processes in metals and alloys with allotropic transformations

摘要

A fast and relatively simple model based on the network simulation method is proposed in this paper to solve numerically non-lineal transient thermal problems, including allotropic transformations, regardless of the temperature dependences of thermal conductivity and specific heat. Piece-wise dependencies for these properties may be assumed since it is difficult to find explicit functions to reproduce them in the whole range of temperatures used in heat treatment work. By taking a large number of stretches in the piece-wise function, the dependencies may be approximated as much as required to the real values reported in the literature or by the manufacturers. Any kinds of boundary condition, lineal or non-lineal, may be added to the model in a simple way. Running the model with appropriate software, the transient temperature field for the whole medium and the heat fluxes in any section are obtained. As regards the convergence of the solutions, no restrictions concerning the time interval need to be imposed by the user. Applications to ductile iron are described in the final section.