On the interstitial induced lattice inhomogeneities in nitrogen-expanded austenite
Research output: Contribution to journal › Article › peer-review
Colleges, School and Institutes
Lattice inhomogeneities, i.e. nitrogen interstitial-induced hexagonal-close-packed martensite (HCP-εN) and shear bands, can form in face-centred cubic nitrogen-expanded austenite (FCC-γN) synthesised on Fe-Cr-Mn and Fe-Cr-Ni austenitic stainless steel (ASS) using triode-plasma nitriding (TPN). Homogenous elemental distribution between HCP-εN and FCC-γN supports the displacive shear transformation mechanism proposed for a high-Mn, low stacking fault energy ASS under nitrogen interstitial-induced deformation. While resulting from transformation-induced plasticity, HCP-εN exhibits similar lattice expansion behaviour to the parent FCC-γN. However, inhomogeneous elemental distributions in the shear bands formed in γN layers on a 400°C TPN-treated high-Ni ASS indicate local migration of substitutional elements.
|Early online date||3 May 2020|
|Publication status||Published - Aug 2020|
- Nitriding, Expanded austenite, Shear banding, Martensitic phase transformation, High-resolution electron microscopy (HREM)