1997 Volume 37 Issue 11 Pages 1107-1111
Cooling rate dependence of the degree of undercooling at the onset of solidification for 18Cr-8Ni stainless steel was numerically analyzed using a classical nucleation theory. Transient time which can characterize the time-dependent behavior of nucleation was evaluated for iron. It is shown that temperature change in the experiment is slow enough against the transient time and no time-dependent behavior can be expected within the predictions by the classical theory. A new model for time-dependent contact angle was proposed so as to reproduce the cooling rate dependence of the degree of undercooling. This prediction model shows a good agreement with the experimental result for 18Cr-8Ni stainless steel. The effect of substrate temperature on the degree of undercooling and the primary nucleation phase of 18Cr-8Ni stainless steel was also discussed using the model.
