A NEW METHOD FOR REVEALING AUSTENITE GRAIN BOUNDARIES BY CORROSIVE GASES

Abstract

In the present investigation, the authors developed a new method for revealing austenite grain boundaries in steel. The method utilized a high-temperature corrosion by means of such corrosive gases as hydrogen chloride or chlorine.
When a polished specimen was kept at high temperature in an inert atmosphere containing a corrosive gas, its surface was more deeply etched at grain boundaries and revealed austenite grains in a few minutes. This method was more simple than other methods.