METHOD OF CIRCULATING IONIC NITRIDING OF METAL ARTICLES AND DEVICE FOR ITS IMPLEMENTATION Russian patent published in 2018 - IPC C23C8/36 C23C14/22 

FIELD: machine building.

SUBSTANCE: invention relates to machine building, in particular to ionic chemical-thermal treatment of metal articles. Method of circulating ionic nitriding of a metal article in a nitrogen medium under the influence of a corona discharge involves carrying out ionization of nitrogen at the pressure from 10⁵ to 10⁶ Pa and the temperature from 500 to 900°C under the influence of a corona discharge formed at the voltage on alternating corona electrodes from 20 to 40 kV and the current on each of the corona electrodes from 100 to 300 mcA, and circulating the nitrogen mixture by the alternating corona electrodes with sharp coronaizing edges connected to a high voltage power source. Nitriding of the metal article is carried out by circulating the resulting ionized nitrogen medium over the surface of the metal article when the alternating corona electrodes are positioned above the processed surface of the said article. Device for carrying out the above-mentioned method comprises a pipe forming a sealed loop with a heater, a pump for maintaining pressure in the medium and a vessel-evaporator for obtaining the nitrogen medium and a pump for pumping the ionized nitrogen medium, herewith it contains dielectric supports with holes for circulation of the nitrogen mixture, onto which the processed metal article is mounted, the alternating corona electrodes with sharp edges connected to the high voltage power source and grounded grid electrodes overlapping the cross section of the loop. Alternated corona electrodes with sharp edges are directed towards the vector of circulation of the gas mixture, above the processed article. Heater is made in the form of a welded set of heat conducting pipes overlapping the cross section of the said loop. Ohmic heater is installed in the central pipe of the mentioned set, and an ammonia-evaporation vessel is used as the vessel-evaporator to obtain the nitrogen medium.

EFFECT: provided is a shorter time for the ion-chemical treatment of metal articles.

8 cl, 5 dwg