Characterization of 17-4PH stainless steel powders produced by supersonic gas atomization

Xin-ming Zhao1), Jun Xu1), Xue-xin Zhu1,2), Shao-ming Zhang1), Wen-dong Zhao1), and Guo-liang Yuan 1) National Engineering and Technological Research Center for Non-ferrous Metals Composites, General Research Institute for Non-ferrous Metals, Beijing 100088, China 2) Beijing COMPO Advanced Technology Co. Ltd., Beijing 100088, China

摘 要：17-4PH stainless steel powders were prepared using a supersonic nozzle in a close-coupled gas atomization system. The characteristics of powder particles were carried out by means of a laser particle size analyzer, scanning electron microscopy （SEM）, and the X-ray diffraction （XRD） technique. The results show that the mass median particle diameter is about 19.15 μm. Three main types of surface microstructures are observed in the powders: well-developed dendrite, cellular, and cellular dendrite structure. The XRD measurements show that, as the particle size decreases, the amount of fcc phase gradually decreases and that of bcc phase increases. The cooling rate is inversely related to the particle size, i.e., it decreases with an increase in particle size.

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