Three-dimensional analysis of proeutectoid cementite precipitates

Serial sectioning and computer-aided visualization of three-dimensional rec onstructions were used to reveal the three-dimensional morphology, connecti vity and distribution of proeutectoid cementite precipitates in a model Fe- 1.34% C-13.0% Mn alloy. Only dendritic grain boundary precipitates and Widm anstatten precipitate morphologies were observed in the present alloy. Unli ke earlier morphological studies of similar alloys, intragranular precipita tes were not observed. Scanning and transmission electron microscopy of dee ply etched specimens corroborated and augmented these results. Three-dimens ional analysis has also made possible the first quantitative three-dimensio nal measurements of cementite precipitates and yielded a more precise class ification of cementite precipitates than was possible with classical two-di mensional techniques. (C) 1999 Published by Elsevier Science Ltd on behalf of Acta Metallurgica Inc. All rights reserved.