Chemicothermal Treatment in a Glow Discharge at Atmospheric Pressure

Modern methods of chemicothermal treatment (CTT) widely use concentrated energy sources that act on local zones of the treated material. In addition to laser, ion-beam, and other surface treatment techniques, glow discharge at atmospheric pressure (1.01 x 10 exp 5 Pa) deserves appropriate attention. This method differs from classical CTT in low-pressure (about 133-1330 Pa) glow discharge (ion nitriding, carburizing, etc.) by the high power density (10 exp 2 -10 exp 3 W/cm exp 2 ) in the cathode spot, which accelerates the treatment process. It should be noted that the installation for treatment in glow discharge can be substantially simplified by eliminating the sealed chamber and vacuum and gas cylinder stations and conducting the treatment in a protective medium. The aim of the present work consisted in studying the possibilities of chamber-free CTT of carbon and alloy steels in an atmosphere of a protective gas obtained by decomposition of carbamide in the discharge plasma.