Numerical Simulation of Carbon Concentration Profiles in Case Layer of Steel 20 RE-Carburized in Multipurpose Furnace with Drip-Feed Atmosphere

The carburizing process has been successfully carried out in multipurpose furnace employing the drip-feed atmosphere with the addition of rare earth (RE). The carbon transfer coefficients (BRE) and mean diffusion coefficient (DRE) were calculated respectively based on the kinetics of the specimens weigh gain per unit area and the carburized layer growth. The results show that the BRE and DRE are all increased on basis of the incorporation of rare earth. In addition, the mathematical models of the carbon concentration profile under different carburizing conditions and the carbon diffusion coefficient DSRE (at x=0 for carburizing time t>0) have been deduced using the profile simulation method. Computer simulation results show that the simulated curves coincide quite well with the experimental data.