Inert Gas Atomization of High-Nitrogen TRIP-Steels

High nitrogen steels with transformation induced plasticity (TRIP) effect have been recently developed within the framework of the project CRC799. These steels are utilized in a form of powder for the needs of this project. Therefore, the current study focuses on the powder production of high nitrogen steels via inert gas atomization process. Specifically, the role of nitrogen content in determination of the basic powder properties and its behavior on the atomization process are investigated. Additionally, the effects of several other process parameters, such as temperature of the melt and gas to metal ratio are discussed. Thereby, the effect of nitrogen content on the median particle size is not confirmed. Meanwhile, an increase in the spraying temperature and a rise in gas to metal ratio lead to a slight decrease in the median particle size. Nitrogen content in the powder is technologically controlled by the atmosphere above the melt before the spraying process. At last, nitrogen shows a significant impact on the phase composition of powder, by stabilizing the austenite phase. The results thus obtained are of high interest for the future application of the designed steels in the powder form.