The present paper deals with a software simulation system with the aim to completely model surface hardening treatment. The system is composed by two integrated physical-kinetic modules. The former is based on the Fourier equation, solved by means of the finite difference method (FDM) in the 3D transient regime and it is suitable to be adapted for each engineering material. The latter is based on the works proposed by Reti and Denis, which are based on a multi-phase transformation model solved by means of the finite difference method (FDM) in the 2D transient regime. The second module is suitable for each heat treatable steels and it is based on the knowledge of the TTT diagrams. It makes possible to predict the microstructure evolutions during the heat cycle and the final mechanical properties into the surface material due to the quenching effect. Each austenite transformation is, as known, time dependent and it is described by means of a set of coupled system of differential equations. The martensite transformation and all the intermediate quenching phases have been modelled and then can be predicted. Besides the tempering effects due to close passes of the laser spot onto the working surface have been taken into account and the ε-carbides precipitation and martensite tempering effect were modelled. The software simulation system was implemented in C++ programming environment by using the Object Oriented paradigm and graphic outputs was implemented by using OpenGL libraries. A mechanical component was laser heat treated, as requested by an industrial supplier, by adopting different solution in order to achieve the required hardened material area. The laser hardened component was then experimentally analyzed by means of micrographies and by hardness profiles measurements.
A numerical model for laser heat treatment of steels with microstructure evolution and the annealing effect / G., Tani; Orazi, Leonardo; G., Campana; A., Fortunato; A., Ascari. - STAMPA. - (2007), pp. 779-789. (Intervento presentato al convegno 5th International Congress on Laser Assisted Net shape Engineering tenutosi a Erlangen, Germany nel 25-28 September).