Martensite quantification, mechanical properties and cold rolling in AISI301 austenitic stainless steel

Austenitic Stainless steel known as AISI 301 are often used as cold rolled foil with very thin thickness (down to 0.2 mm). Such materials are further shaped by bending or stamping and need to show a suitable deformability even at the cold hardened stage as is the case of the commercialized product. The quantification of the martensite, precipitated as main by product of the cold deformation of the metastable austenitic microstructure, is considered of dramatic importance to predict the toughness of this alloy. In this paper an original method to quantify the martensite by using the magnetic susceptibility (SQUID) is presented and the combination of the so collected data with stress-strain curves on differently deformed samples are discussed. The conclusions introduce the role of cold hardening in volume fraction.