METHOD FOR PROCESSING METALLIC PARTS WITH AN ELECTRIC ARC AND APPARATUS FOR REALISING THE SAME

摘要

The present invention pertains to the field of metal processing and essentially relates to a method that uses an electric arc for processing parts and preforms of different shapes and dimensions in order to remove oxide layers of various types as well as dross and fouling from the surfaces to be processed. This invention increases the quality and the yield of the surface cleaning of metal parts having various configurations, cross-sections and lengths, which is achieved by increasing the density and the distribution regularity of the cathodic spots per surface-area unit of the surface to be processed, by increasing the displacement rate of said spots and by increasing the specific value of the ionic current proportion of the arc. The method involves processing the part at a pressure lower than the atmospheric one and displacing in a controlled manner the arc discharge and the part to be processed relative to each other. The method also involves generating a frequency-pulse component of the voltage and the current in the arc working-current circuit and/or using the quasi-anode effect. The apparatus for realising this method includes a power supply provided with a voltage converter and a current controller, as well as an anode having a special structure for generating the arc discharge between the parts and the quasi-anode. This method is environment-friendly and the waste produced consists of metal oxides in the form of a powder free from aggressive chemical components. It is further possible to combine this cleaning method to a vacuum protection spraying process.