Deformation Structure of Chromium-free High-nitrogen Austenite in Fe–N Binary Alloys

Planar slips have been frequently recognized in nitrogen-added austenitic stainless steels, often influenced by stacking-fault energy (SFE). On the other hand, nitrogen addition promotes the formation of N-Cr short-range order (SRO), also proposed as a critical factor to contribute to the planar slips. In this study, a specified nitriding technique was performed to fabricate a chromium-free Fe-N binary austenite with 2.4 mass% of fully solid-solutioned N to simplify the relationship among deformation structures, SFE and N-Cr SRO. Wavy slips were found in the Fe-N alloy, which can be explained by its SFE, 44.6 mJ/m2. Planar slips were found in nitrogen-added austenitic stainless steels with almost the same SFE, 42.9 mJ/m2 suggesting that N-Cr SRO rather than SFE seems to be the main reasons causing the planar slips.