| About this Abstract |
| Meeting |
MS&T21: Materials Science & Technology
|
| Symposium
|
New Frontiers in Physical Metallurgy of Steels
|
| Presentation Title |
Nano-precipitation and Resultant Surface Hardening by Nitriding of Ferrous Alloys |
| Author(s) |
Goro Miyamoto, Tadashi Furuhara |
| On-Site Speaker (Planned) |
Goro Miyamoto |
| Abstract Scope |
Nitriding treatment is commonly used to increase surface hardness for improvement of fatigue strength and wear resistance. In the nitriding of ferrous alloys containing strong nitride forming element (M), surface hardening occurs by precipitation of fine nitrides. The present authors directly observed that surface hardening in the nitriding of Ti or V-added specimens occurs not by the precipitation of stable alloy nitrides but of meta-stable mono-layer M-nitrogen(N) clusters by means of high resolution transmission electron microscopy. On the other hand, clustering was not observed in Al-added specimens, meanwhile in nitriding of Fe-Al-(V, Ti) alloys, formation of V-N or Ti-N clusters in the early stage of nitriding induces nucleation of fine AlN particles, which results in significant surface hardening. This indicates pre-cursor solute clustering can be used to control precipitation reaction in ferrous alloys. |