Austenitic spotless steel is the biggest group of treated steels, making up around 66% of all tempered steel creation (see creation figures below). They have an austenitic microstructure, which is a face-focused cubic precious stone structure. This microstructure is accomplished by alloying steel with adequate nickel and additionally manganese and nitrogen to keep an austenitic microstructure at all temperatures, going from the cryogenic area to the liquefying point.Thus, austenitic treated steels are not hardenable by heat treatment since they have the equivalent microstructure at all temperatures
