Metallographic screening of grain boundary engineered type 304 austenitic stainless steel

• As-received (annealed) and grain boundary engineered microstructures were compared.
• Electro-chemical polarisation in nitric acid solutions was carried out.
• A metallographic screening method has been developed.
• The screening method complements EBSD analysis for microstructure identification.

An electrochemical etching method for the identification of grain boundary engineered type 304 austenitic stainless steel microstructures is described. The method can be applied for rapid microstructure screening to complement electron backscatter diffraction analysis. A threshold parameter to identify grain boundary engineered microstructure is proposed, and the application of metallographic etching for characterising the degree of grain boundary engineering discussed.