Method of and apparatus for heat treating axisymmetric surfaces with an annular laser beam

摘要

This invention is directed to a method of and apparatus for heat treating axisymmetric surfaces such as inner and outer surfaces on pipes, shafts, gears, valve seats and the like with a laser beam. An annular laser beam is provided and caused to impinge on a segmented generally conical mirror which focuses and/or directs the laser beam onto the desired surface of a work piece as an annular or ring-shaped beam with a predetermined width and energy profile. Relative movement about the axis of the laser beam may be provided between the work piece and the laser beam to average any intensity distributions around the laser beam. Additionally, relative movement along the axis of the laser beam may also be provided between the work piece and the laser beam in the case of shafts, pipes and the like to provide uniform and non-overlapping coverage of the surface to be treated.