Characteristics of Solution Nitriding and Properties of the High Nitrogen Stainless Steel

Solution nitriding (nitrogen absorption treatment) is one of the techniques to produce high nitrogen stainless steels. In this article, the merits and problems of solution nitriding, the general theory and phenomenon of nitrogen absorption, and the properties of solution-nitrided high nitrogen austenitic steels were reviewed on the basis of the results obtained by authors in the recent research. Especially, the thermodynamics and kinetics of nitrogen absorption were emphasized because of their importance in the production of solution-nitrided materials. In addition, the potential of high nitrogen steels produced by solution nitriding was also briefly discussed in terms of the prospective application of nickel-free stainless steels to fine or micro-sized structural materials for biomedical uses.