Study on absorption and transport of carbon in steel during gas carburizing with rare-earth addition

The effect of rare-earth (RE) as a catalyst adding to carburizing atmospher e on absorption and transport of carbon is presented in this paper. The pro cessing were carried out at 900 degreesC for different time in a decomposit ion atmosphere of kerosene and methanol with and without RE addition. The c ompositions of carburizing atmosphere such as CO, CH4, etc, and the average carbon concentrations in 75 mum thick 08F steel foil were measured by infr ared and chemical analysis, respectively. The surface activity and boundary transfer coefficient of carbon have been calculated based on the measured data. The results show that introducing RE into carburizing atmosphere incr eases the volume fraction of CO, CH4. etc. degree of dissociation of kerose ne, carbon potential, surface activity and boundary transfer coefficient of carbon. (C) 2001 Elsevier Science B.V. All rights reserved.