THERMAL-STABILITY OF MANGANESE-STABILIZED STAINLESS-STEELS

Previous work on experimental high-manganese reduced-activation austen itic stainless steels demonstrated that they had improved tensile prop erties relative to type 316 stainless steel (316 SS) in both the annea led and 20% cold-worked conditions. Seven steels were tested, which in cluded an Fe-20Mn-12Cr-0.25C (in wt%) base composition, and this compo sition with various combinations of Ti, W, V, P, and B. Tensile tests have now been completed on these steels after thermal aging to 5000 h at 600 degrees C. Thermal stability varied with composition, but the a lloys were as stable or more stable than 316 SS. After aging to 5000 h at 600 degrees C, the strength of the annealed steels increased sligh tly, and the strength of the cold-worked steels decreased. In both con ditions, a steel with a combination of all the alloying elements had t he best strength after thermal aging. Despite having higher strength t han 316 SS after aging, the ductility of the strongest alloy was still as good as that of 316 SS.