Abstract
A new observation method was developed for evaluating precipitates distributions on the electropolished surface of the ferritic heat-resisting steel (9Cr-3W) , using field emission type-scanning electron microscopy (FE-SEM) . The FE-secondary and backscattered electron images of the electropolished surfaces visualize clearly fine precipitates, since the electropolishing surfaces are very flat and not influenced by martensite matrix surface unevenness.
The intergranular or transgranular precipitates distributions for each of the two types of chromium carbide and laves phase which were identified by backscattered electron images, were quantitatively evaluated, respectively, before and after the creep-fatigue testing.
