Characterization of precipitate distributions for ferritic heat-resisting steel with superior to creep-fatigue property

摘要

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.