Carpenter Guide to Electrolytic Etching of Specialty Alloys; Principles, Procedures, and Special Applications

Electrolytic etching is a valuable technique in metallurgical examination, particularly for the preparation of stainless steel, nickel, cobalt, and other corrosion resistant alloys for microstructural analysis. This talk explores the principles and applications of electrolytic etching in revealing detailed microstructures, including selective phase etching, grain boundaries, and precipitate behavior. The discussion will include the role of etching parameters—such as etchant solution, cathode selection, voltage, and current density—in optimizing the process in order to produce accurate and reproducible results.

Special attention will be given to ASTM A262 Practice A, a standard screening practice for the susceptibility of intergranular corrosion. Case studies will demonstrate the application of electrolytic etching for metallurgical examinations of various Carpenter alloys, illustrating the technique’s role in revealing critical microstructural features. Attendees will gain a deeper understanding of how electrolytic etching can be used in metallographic analysis.