The m phase layer on ion nitrided austenitic stainless steel (III): an epitaxial relationship between the m phase and the γ parent phase and a review of structural identifications of this phase

摘要

As we previously confirmed, the fl? phase, forming as a single-phase layer upon ion nitriding of AISI 316L stainless steel under mild conditions, has a centered tetragonal structure with strong composition dependence of the axial ratio, c/a, and, as recently reported, a strong duplex {111} and {100} texture normal to the surface with a surprisingly strong in-plane directional component. This texture is now demonstrated to be an extension of a corresponding duplex texture of the austenitic γ parent phase, with m growing epitaxially on and into the γ phase. Since there are some other interpretations of the γ phase structure in the literature, a comparative discussion and additional data are given in Appendix A.