Effect of dissolved cerium on austenite grain growth in an Fe-0.20 mass%C-0.02 mass%P alloy

The effects of dissolved cerium on the kinetics of austenite grain growth a nd on the grain size and grain shape distributions were studied at 1 473, 1 573, and 1 673 K in an Fe-0.20mass%C-0.02 mass%P alloy containing a limite d amount of second-phase particles as a function of holding time. The mean planar grain diameter (D-mean) for a given holding time decreased considera bly with the addition of dissolved Ce up to 300 mass ppm and then decreased gradually. The parabolic law kinetics was observed and its apparent rate c onstant was inversely proportional to the content of dissolved Ce in atomic pet. The spatial grain size distribution obtained by the Johnson-Saltykov transformation could be best described by the log-normal distribution funct ion and normal grain growth was observed. The D-max/D-mean (D-max: the maxi mum grain diameter) value was independent of the content of dissolved Ce an d holding time. The distribution of the number of grain sides was observed to be holding time-invariant and was not affected by the presence of dissol ved Ce.