Mechanical properties of high-nitrogen steel produced via selective laser melting using mechanically alloyed and spheroidized powders

Abstract

In recent years, the development of additive technologies has been one of the priority tasks in the sector. Primarily, additive technologies enable the effective implementation of various design and engineering ideas in high-tech industries, such as the aircraft industry, engine technology, and rocket engineering. The expanded range of standardized materials for additive technologies will facilitate their integration into large-scale production. Of significant interest is the potential use of nitrogen-containing heat-resistant powder alloys to produce complex-shaped aircraft parts using additive technologies. This paper describes the complete process of obtaining samples from powders of alloys with superequilibrium nitrogen content using the selective laser melting (SLM) method. Four different compositions of high-nitrogen steels were obtained through mechanical alloying. Subsequently, the powders of these steels underwent processing using the plasma spheroidization method to be utilized in the SLM process. The SLM method was also employed to produce samples for mechanical tests. Throughout each stage of the process, the powders were thoroughly analyzed. One of the most critical parameters was the nitrogen content in the resulting powders. At each subsequent production stage, its proportion decreased, yet it remained at the superequilibrium content level of 0.13–0.44 wt. %. The mechanical tests confirmed that the alloys fabricated by the SLM method are not inferior in terms of their properties compared to those obtained using classical metallurgical technologies.