Abstract: arburising experiments were conducted for six sorts of carburising materials in com-mon use at temperature 930℃,and established the control model of surface carbon concentration. The usual form is Cp=Cs=C0- Along with the extending of carburising time,the surface carbon concentration was going up in the parabolic law. When the carburising material,the carbon potential changes,the two factors C_0 and K are changed,the surfaee car-bon concentration is affected. In addition,the carburising equilibrium time (the time of surface carbon concentration) was studied.The carburising equilibrium time had mainly something to do with carburising material and carbon potential.

Key words: surface diffusion, carburizing, chemical equilibrium