Affiliations: National Institute for Materials Science, Tsukuba, Japan
Note: [] Address for correspondence: Megumi Kimura, National Institute for Materials Science (NIMS), 1-2-1, Sengen, Tsukuba 305-0047, Japan. Tel.: +81 29 859 2246; Fax: +81 29 859 2201; E-mail: Kimura.Megumi@nims.go.jp.
Abstract: A new observation method was developed for evaluating precipitate distributions on the electropolished surface of ferritic heat-resisting steel, using field emission scanning electron microscopy (FE-SEM). FE-secondary and backscattered electron images of the electropolished surfaces clearly reveal fine precipitates, since the electropolishing surfaces are very flat and not influenced by martensite matrix surface unevenness. The intergranular or transgranular precipitate distributions for each of two types of chromium carbide and Laves phase, which were identified from backscattered electron images, were quantitatively evaluated for the material with superior to a creep–fatigue property, before and after a creep–fatigue testing, respectively.
Keywords: Creep–fatigue, ferritic heat-resisting steel, microstructure, precipitates, grain boundary, electron microscopy, backscattered electron