Dissolution and precipitation of excess phases and the nitrogen distribution between a solid solution and nitrides in a corrosion-resistant steel

The dissolution and precipitation of nitrides are experimentally studied during the solidification and heat treatment of high-nitrogen austenitic steels. The majority of nitrogen is found to be in nitrides even upon rapid solidification, and the dissolution of these nitrides requires high temperatures and long-term holding. The nitrogen content has to be optimized according to the required steel structure, namely, austenite or austenite + excess phases. A high nitrogen content in a steel is not always effective to provide its high strength.