Patent ID: 6469274
Filing Date: 2002-10-22
Classification: B23K

Abstract:
A process for the plasma oxycutting of at least one metal workpiece containing at least one ferrous metal, in particular iron, in which:(a) an ignition region of the metal workpiece to be cut is locally preheated by subjecting said ignition region to at least one plasma jet; (b) at least part of the ignition region at least preheated in step (a) is subjected to at least one stream of oxidizing gas at a pressure of greater than 105 Pa; (c) at least one drillhole is made over the entire thickness of the workpiece to be cut, in at least part of the ignition region subjected to at least preheating by plasma jet in step (a), by melting and/or combustion of the ferrous material contained in said metal workpiece by the reaction of said ferrous material with said stream of oxidizing gas and/or said plasma jet; (d) the plasma jet and the stream of oxidizing gas are moved in a cutting path in order to produce at least a portion of a kerf through said workpiece by melting and/or combustion of the ferrous material contained in said metal workpiece by means of the reaction of said ferrous material with at least said stream of oxidizing gas; and (e) the ignition region is preheated in step (a) to a temperature of between 1000 Â° C. and 1500 Â° C., preferably from 1200 Â° C. to 1400 Â° C. and even more preferably about 1300 Â° C. to 1350 Â° C. and/or in that the preheating time is between 0.001 and 2 seconds, preferably between 0.01 and 1.5 seconds.