Non-destructive techniques for the detection of sigma phase in duplex stainless steel: A comprehensive review

Sigma phase is a deleterious phase which can be formed in duplex stainless steels (DSSs) during heat treatment, manufacturing, or welding processes, leading to a decrease of mechanical properties and corrosion resistance. This issue is highly concerning for numerous industries because the presence of σ–phase in the austenite/ferrite microstructure of DSSs reduces their lifetime and promotes a brittle fracture in service. This review focuses on...