Control Of Nitrogen Alloying In Additive Manufacturing Of Austenitic Nickel-Free Stainless Steel

Nitrogen-alloyed austenitic nickel-free stainless steels (ANFSS) are known for their good corrosion resistance and mechanical properties, and stable non-magnetic nature. As long as the nitrogen content remains within certain limits, increasing the nitrogen content generally improves all the said properties. However, if the nitrogen content is increased up to a too high level, ductile-to-brittle transition may take place. The optimal nitrogen level is determined by other alloying elements that can have a role in stabilizing the austenite and increasing nitrogen solubility in the melt during manufacturing. In this research, we investigate how to control the nitrogen content of nominally Fe-16Mn-14Cr-0.27C-0.35N steel during direct energy deposition processing using the mixtures of powders representing the nominal composition and subjected to a nitriding treatment. An emphasis is placed on the corrosion and mechanical properties of the resulting alloy, which we aim to explain by the analyses of material chemical composition and microstructure.