1996 Volume 82 Issue 3 Pages 244-248
In order to establish an appropriate process for observation of distribution of σ-phase particles in austenitic stainless steels, which enables observation of a large numbers of specimens in a short time, extraction replica methods combined with image-processing technique were explored. Obtained results are as follows:
(I) For σ-phase in SUS316H steel, any of the following three extraction method works satisfactorily : (1) electrolytic etching by 10%acetylacetone-1%HCl-metanol followed by extraction by the same electrolyte ; (2) etching by 10%Br2 -ethanol solution followed by extraction by Villella's solution : (3) etching by Villella's solution followed by extraction by the same solution.
(II) For σ-phase in SUS304H and SUS321H steels, the third method above is suitable.
(III) For exclusive observation of the σ-phase particles from other coexisting M23C6, TiC and Laves phase particles, image-processing is useful.
