2005 Volume 77 Issue 6 Pages 381-386
The major part of decarburization in spheroidal graphite cast iron at high temperature is caused by the diffusion control1ed growth of the decarburized layer. The parabolic growth rate of the decarburized layer in one dimension is formulated as a function of the relative solubility and diffusion coefficient of carbon in austenite. At lower temperature, the growths of ferritic and austenitic layers promote decarburization, the rates of which are calculated. The calculated growth rates at varied temperature are in fair coincidence with the experimental data of prior investigators. Computer simulation shows that the holding time of heating to annihilate al1of the graphite nodules is reduced by increasing the solubility and diffusion coefficient of carbon, and is proportional to the dimension square and the ratio of volume to the surface area of the casting.
