Abstract
Systematic studies on internal oxidation/nitriding of alloys at low temperatures have not been reported in contrast to high temperature oxidation/nitriding reported so far. However, the oxidation/nitriding at low temperatures has great advantages on discussion of the diffusion process of dissolved oxygen in α-Fe and the formation of nanoparticles of oxide/nitride which effects upon various properties of the alloys.
In this paper, characteristics and mechanism of internal oxidation/nitriding behavior are explained. Next the determination of oxygen diffusion coefficient in α-Fe by using internal oxidation of three different alloys is introduced on the basis of the oxidation rate equation and the thermodynamic data. Furthermore the development of novel Mo alloys having high ductility and high strength due to microstructure controlling by distribution of small nitride particles through a new multi-step nitriding method is also described.
