Laser surface hardening of large cylindrical components utilizing ring spot geometry

A new process, based on ring spot geometry, is presented for laser surface hardening of large cylindrical components. The proposed technique leads to a very hard, deep and uniform hardened layer along the entire work piece surface without introducing a tempered zone, making the process very attractive compared to conventional induction hardening that exhibits both low energy efficiency and poor flexibility. A complete physical model is presented for the process, together with a study of the influence of process parameters on the final outcome. The results of an extensive validation campaign, carried out on AISI 1040 specimens, are also reported.