Analysis of deuterium induced nuclear reactions giving criteria for the formation process of expanded austenite

High current ion nitriding of austenitic stainless steel at temperatures of about 400°C leads to the formation of a surface layer, called expanded austenite. The formation of this layer is not well understood. Deuterium induced nuclear reaction analyses have been performed on austenitic stainless steel samples that were subsequently high current ion nitrided with low energy ion implantation of 15 N and 14 N. The obtained depth profiles yield criteria for the formation process of the expanded austenite. A trapping mechanism cannot be confirmed.