Abstract
To reveal the prior-austenite grain boundaries in micro-alloyed steels there is different techniques. This study has been carried out over a wide range of temperature (950- 1150 οC) and it has been found that the tested procedure based on the combination of heat treatment and thermal etching (TE) method give excellent results for the Titanium and Titanium free medium carbon micro-alloyed steels at all the austenitization conditions tested.