METHOD OF IMMEDIATELY INITIATING A THERMOCHEMICAL REACTION ON A SURFACE OF METALLIC WORKPIECE AND APPARATUS THEREFOR

摘要

A method and apparatus for making an instantaneous thermochemical start on the surface of a metal workpiece.P PThe method resides in the use of laser beam focused to a small spot to bring the ferrous workpiece to ignition temperature in combination with a high intensity oxygen jet to cause the initiation of the thermochemical reaction. The laser beam may impinge the workpiece at a point about 1 cm behind the spot where the oxygen impinges the workpiece surface to a point about 10 cm ahead of such spot. Accordingly, the laser beam may penetrate the high intensity oxygen jet and still cause the thermochemical reaction to start instantaneously.PPThe apparatus resides in a scarfing machine having a scarfing nozzle, an oxygen spreader nozzle and a laser assembly associated therewith. The oxygen spreader nozzle is mounted so as to provide high intensity oxygen jet on the surface of the workpiece ahead of the scarfing oxygen effluent from the scarfing nozzle. The laser assembly is mounted so that its optical system will direct a laser beam on the surface either ahead or behind the point of impingement of the oxygen jet.