METHOD AND DEVICE FOR PLASMA-THERMAL TREATMENT OF ARTICLES Russian patent published in 1997 - IPC

FIELD: plasma treatment of metal articles. SUBSTANCE: this treatment is used for surface hardening of articles, primarily metal without formation of cracks, with achieving high hardness and improvement of other physico-mechanical properties. Thermal treatment is effected without direct action of electric arc upon surface of article. According to method, surface of article is heated by electric arc with current at level of 30-600 A, and it is fixed in close-to-cathode area, then it is reciprocally moved at amplitude equal to not over 250 mm in close-to-anode area above surface of article with variable field in direction which is perpendicular to advance movement of article relative to electric arc. Electric arc in close-to-anode area is subjected to action of permanent magnetic field. It is moved off article surface by at least 3.0 mm. Anode spot is located on anode, axis of cathode is directed at angle to treatment plane, hot gases from close-to-anode area are moved above article surface, linear speed of advance movement of article relative to electric arc is set as equal to 0.1-25.0 cm/s. Depending on configuration of article being treated, anode spot is positioned at distance of 1.0-25.0 mm from its surface. EFFECT: high efficiency. 1 cl, 4 dwg