“Boost-diffusion” vacuum carburising - Process optimisation

The article presents the optimisation of the organisation of the vacuum carburising process in terms of the number and duration of “boost”/“diffusion” stages. The processes of two- and multi-segment carburising were examined with regard to the process duration and effectiveness of carbon transfer from the atmosphere to the charge surface. It was shown that division of the process into two segments (1 boost + 1 diffusion) results in extending the total process time, regardless of the carburising temperature. The total time and effectiveness of the carburising process depends on the minimum, momentary surface concentration of carbon, achieved in the diffusion stage.