Laser Hardening Simulation for 3D Surfaces of Medium Carbon Steels Industrial Parts

This paper refers to a 3-D transient model for laser surface hardening of mechanical components. The model makes it possible to predict the hardened depth into the bulk and the extension of the treated area together with the resulting microstructures with respect to the laser parameters and to the laser beam path strategy. The hardness reduction due to the tempering effects in the overlapping trajectories can be estimated. The solution of the heat flow problem into the bulk and the solution of the solute diffusion problem into the transforming phases are obtained by means of two independent meshes. The mesh generator was developed to manage complex geometry. The initial work-piece microstructure is taken into account in the simulation by a digitized photomicrograph of the ferrite-pearlite distribution before the thermal cycle. In order to validate the model, experimental trials were conducted on the keyway for spline machined on a hub made in C43. The model generates a part program in ISO base code to directly command the laser source and the controlled axes for the work-piece displacements.