2006 Volume 92 Issue 4 Pages 268-273
In order to develop effective ways to estimate carbon distribution in vacuum carburized steel, the surface interaction during vacuum carburizing was investigated. 0.1 mm thick specimens were vacuum carburized for sufficiently long time. The carbon content and carbide area fraction of specimens proved to be the value in equilibrium with graphite. This result shows that the graphite exists while vacuum carburizing on the surface of specimens, and that the local equilibrium between specimens and graphite is dominant factor. Carbon profile of carburized round bar was calculated on the basis of diffusion equation, on the assumption that surface carbon content is as much as the value in equilibrium with graphite. The calculatuied carbon profiles correspond to measured ones for some materials and carburizing conditions.
