Austenite Grain Size Distribution and Topological Properties in Fe-0.09 to 0.53mass%C-0.02mass%P Alloys Containing Primary Inclusions of Ce2O3 and CeS.

Abstract

The effects of the primary inclusion of Ce 2 O 3 (the mean planar diameter, đ A =1.6 to 2.1 μm) or CeS (đ A =2.2 to 2.8μm) particles on austenite grain size and grain shape distributions were studied in Fe-0.09 to 0.53 mass%C-0.02 mass%P alloys, which were continuously cooled from 1 873 to 1 673 K, followed by holding for 0 to 180 min. It was found that the shape of the relative spatial grain size distribution, D V /D V,mean (the mean grain diameter), was invariant with respect to the content of carbon, the number of Ce 2 O 3 or CeS particles (the volume fraction of particle, f V =0.02 to 0.19%) and holding time. The spatial grain size distribution could be best described by the log-normal distribution function. The heterogeneity parameter, D max (the maximum grain diameter)/D V mean ratio in three dimensions, increased with an increase in the f V value. The distribution of the number of grain sides and the grain size distribution for each grain side follow approximately the log-normal distribution function, and these results were consistent with those observed in previous experimental results for normal grain growth, in which a second-phase particle was not present.