NITRIDING OF Fe-Mn ALLOY AND PURE-Ti

Abstract

For better life and serviceability, many engineering components should be provided with improved properties in the surface adjacent region of the component, as this is usually the location of most severe loading. Thus a hard case on a soft core can induce pronouncedly improved mechanical performance. The outer hard case enhances the wear and fatigue resistance while the soft core bulk" retains the toughness to bear the impact loads. I-lard cases can be produced on many steel components for example by thermochemical diffusion treatments such as nitriding, carburizing, nitrocarburizing and carbonitriding, which are widely employed in the industry. Although these processes have been well established in industrial practice, fundamental understanding of the underlying micro-mechanisms is fragmentary which is due to the presence ola large number of alloying elements in commercial steels, which leads to complex interactions between inwardly diffusing species (N and C) and alloying elements. Fundamental studies have been carried out on simple model systems, such as pure iron 11 -41, iron based binary [5-7] and ternary [8-101 alloys to understand the underlying phase transformations, which lead to the modification of the substrate microstructure upon thermochemical treatment