Laser hardening of large cylindrical martensitic stainless steel surfaces

This paper deals with laser surface hardening process of martensitic stainless steel. The heat treated components are cylindrical with a thin thickness. The heat treated area is larger than the laser spot dimension and for this reason multi-tracks or virtual spot technique are needed in order to process the whole surface. The typical problems of such a hardening method, concerning quenching and tempering involved phenomena, are faced and scanning strategies optimization are considered. The process optimization has been carried out by using a Laser Hardening Simulator (LHS) developed by the Authors. LHS allows to simulate the laser-material interaction in order to calculate the heat cycle into the bulk material and then the resulting micro-structures after the heat treatments according to laser scanning trajectories.