The present work is aimed at refining the grain size in the Co–28Cr–5Mo–0.3C (wt%) cast alloy using particle-stimulated nucleation (PSN) of recrystallization. It is pointed out that PSN resulted in considerable grain refinement (≈80%) of the as-cast structure, leading to an increased yield and tensile strength (around 30%). Partial solutionizing is associated with the formation of γ_fcc and athermal martensite. During PSN, the intensity of the hexagonal close-packed (hcp) phase increases due to the formation of isothermal martensite. It appears that new dynamic recrystallized (DRX) grains are formed around coarse undissolved particles (≈10 μm in size), especially where these particles are present in large clusters. The high-resolution TEM image shows the formation of heavily faulted regions and subgrains, with maximum misorientation near the carbides providing the driving force for the nucleation of new grains.

中文翻译：

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Co–28Cr–5Mo–0.3C合金中的颗粒激发形核（PSN）

目前的工作旨在通过使用颗粒刺激形核（PSN）来细化Co-28Cr-5Mo-0.3C（wt％）铸造合金的晶粒尺寸。需要指出的是，PSN使铸态组织的晶粒细化（约80％），从而提高了屈服强度和抗拉强度（约30％）。部分固溶与_γfcc的形成有关和无热马氏体。在PSN期间，由于等温马氏体的形成，六方密堆积（hcp）相的强度增加。似乎在未溶解的粗颗粒（尺寸约10μm）周围形成了新的动态重结晶（DRX）晶粒，尤其是在这些颗粒以大簇存在的情况下。高分辨率TEM图像显示出严重断层区域和亚晶粒的形成，碳化物附近的最大取向不良为新晶粒的成核提供了驱动力。