Anomalous low temperature elastic-constant behaviour of Fe-20Cr-16Ni-6Mn

Abstract

For the high nickel content austenitic stainless steel Fe-20Cr-16Ni-6Mn (wt-%), the complete set of polycrystalline elastic constants between 295 and 4 K were determined ultrasonically. A reversible magnetic transition occurs near 54 K. During cooling, the bulk modulus begins to soften at a much higher temperature, near 150 K. Local moments above the transition temperature may explain this peculiarity.