PURPOSE: To allow the sampling and microscopic inspection of a change in metallic structure and metal defect even in the corner positions where materials form perpendicularity or curvature by applying a prescribed mixture consisting of cellulose acetate and the balance an org. solvent on the surface of a specimen corroded by an etching soln. after grinding.
CONSTITUTION: The surface of the section where the specimens intersect with each other at the curvature is buffed, cleaned and dried and thereafter, the surface is corroded by the liquid mixture composed of 3 to 7wt.% cellulose acetate clay and the balance acetone. The voids 2 by the creep damages of the specimens, the precipitation of carbides 3, and extremely slight flaws are then distinctly produced and even the section which is heretofore impossible to be microscopically inspected is easily microscopically inspectable.
FUKUDA KIYOSHI
MURAMATSU MASAMITSU
