Magnetic properties of α′ martensite in austenitic stainless steel studied by a minor-loop scaling law

We study the scaling behavior of magnetic minor hysteresis loops in strain-induced ferromagnetic α′ martensites in an austenitic 316-type stainless steel. A scaling relationship between the hysteresis loss and the remanence, with a power law exponent of approximately 1.35, was found irrespective of the volume fraction of the α′ martensites as well as temperature. The coefficient of the power law largely decreases with volume fraction, whereas it increases with a decrease in temperature and exhibits a kink at around 40 K, close to the Néel temperature of an austenitic γ′ phase. The behavior of the coefficient was interpreted from the viewpoint of the morphology and exchange interaction of α′ martensites.