Low-activation Mn–Cr austenitic stainless steel with further reduced content of long-lived radioactive elements

Abstract Low-activation austenitic stainless steel based on Mn–Cr non-magnetic steels has been developed. The alloying elements of long-life activation, such as Ni, Mo and Co, were eliminated and substituted with Mn along with an addition of N. A Mn–Cr austenitic stainless steel, 24.5Mn–13.5Cr–0.02C–0.2N, has been developed successfully. Examined material properties, including mechanical, thermal and magnetic properties, as well as weldability and characteristics of corrosion resistance, are presented. It was found that the alloy has excellent material properties virtually equivalent to those of 316SS. In this study, the applicability of the Schaeffler, DeLong and Hull constitution diagrams for the stainless steels with low Ni and high Mn contents was also examined. The boundary conditions distinguishing the single austenite phase from the others have been identified for the Mn–Cr steels.