Production and characterization of SUS 439 powders by gas atomization process

Gas atomization is the conventional and well-known methods to produce metal powders. This method can be used to get high sphericity and fluidity of the powders. The metal powders produced by the gas atomization have a rapid cooling rate because of fast heat transfer between the droplets and the injected gases. The gas atomization can be used to produce various metal powders with melting temperatures below 1700°C such as aluminum and copper alloys, nickel alloys, and stainless steels etc. Usually the stainless steel powders for metal injection mould process have been also produced by the gas atomization. In this paper, we produced the SUS 439 using the gas atomization process. Due to the high strength and good corrosion resistance of the SUS 439, it has been used widely in various applications, especially in automobile, military and aerospace instruments. As-prepared gas atomized powders were observed through visual identification method. Microstructure of the powers was observed by optical microscopy, size and size distribution and shape were observed by FE-SEM and LPSA. Phase of the powers was analyzed by XRD. Sintering behaviors were checked also with sintering conditions.