Choice of Boundary Condition for Solving the Diffusion Problem in Simulation of the Process of Vacuum Carburizing

Comparative analysis of three kinds of boundary condition for solution of the diffusion equation in a mathematical model of vacuum carburizing (low-pressure one) is performed for plotting the carbon concentration curves in carbon and alloy steels. With allowance for the special features of mass transfer in formation of the diffusion layer and for the effect of control factors of the carburizing process, the mass transfer coefficient in the equation of the boundary condition of the third kind is evaluated with the help of parametric equations.