Process For Hardening An Annular Groove Of A Piston Head By Means Of Laser Beams And A Piston Produced By The Process

Abstract

The invention relates to a process for hardening an annular groove of a piston head (1) of a steel piston of an internal combustion engine by means of laser beams (4), in which, according to the invention, at least the annular groove to be hardened is provided before or directly during hardening with a coating which absorbs the energy of laser beams (4) and the coating is subsequently irradiated with the laser beams (4). The absorbing layer is preferably a manganese phosphate coating or is formed in situ by treating the component surface with a process gas comprising oxygen and inert gas. Furthermore, the laser beams are directed at the piston during hardening at an oblique angle to the direction of rotation. The advantages achieved are: avoidance of reflections and undesirable hardening of the bottom of the rotation. The advantages achieved are: avoidance of reflection and undesirable hardening of the bottom of the groove, an increased degree of absorption and reduced distortion of the piston.

Dependencies are inferred from the claim text.