Numerical simulation of carbon concentration profiles in case layer of steel 20 RW-carburized in multipurpose furnace with drip-feed atmosphere

摘要

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 ( beta ~RE) and mean diffusion coefficient (D~RE) 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 beta ~RE and D~RE are all increased on basis of the incorporation of rare earth. In addition, the mathermatical models of the carbon concentration profile under different carburizing conditions and the carbon diffusion coefficient D_S~RE(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.