Influence of Mechanical Alloying Time on Morphology and Properties of 15Cr-ODS Steel Powders

Abstract

AbstractOxide dispersion strengthened (ODS) ferritic steels are the leading candidates of fuel cladding for Generation IV nuclear reactors due to their excellent properties such as excellent radiation tolerance and high-temperature creep strength. Mechanical milling with the aim of a fine dispersion of oxides in the metal matrix becomes the main process for the production of ODS steels. In order to clarify the influence of milling time on the precursor powders for 15Cr-ODS steel, the morphology and properties of mechanical alloying (MA) powders with different milling time were investigated by scanning electron microscopy (SEM), laser diffraction particle size analyzer, X-ray diffraction (XRD) and Vickers hardness tester. The experimental results showed that the powder was fractured and welded with rotation and vibration of container during mechanical milling. The mean powder size increased (0–1 h) firstly then decreased (2–60 h). Extending milling time to 70 h, the mean powder size increased again. The grain size decreased quickly at the initial stage of milling process (0–2 h) then trended to reach a saturation value. The Vickers hardness increased rapidly at the initial stage of milling, then reached a saturation value.