This study explores the effects of Fe ion irradiation and helium implantation on the mechanical and microstructural behaviors of K-RAFM steels. Through micropillar compression tests, we observed irradiation hardening, which manifested as an increase in strength and a decrease in strain bursts in the irradiated specimens. This change in deformation behavior indicates the impact of radiation-induced defects on dislocation dynamics. Helium implantation resulted in the formation of surface steps and, as shown by nanoindentation mapping, led to a localized increase in hardness, highlighting the significant influence of helium on mechanical properties. Microstructural examination revealed the steel's tempered martensitic structure and pointed to the importance of MC and MX precipitates in modulating the effects of irradiation. Notably, K-RAFM steels showed a diminished extent of irradiation hardening, which can be attributed to the higher fraction of MX precipitates serving as effective trapping sites for point defects. Understanding how microstructural features influence mechanical performance in K-RAFM steels assists in steering the creation of materials tailored to improve radiation resistance in nuclear environments.

中文翻译：

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K-RAFM 钢对铁离子辐照和氦注入的机械和氦膨胀响应

本研究探讨了 Fe 离子辐照和氦注入对 K-RAFM 钢的机械和微观结构行为的影响。通过微柱压缩试验，我们观察到辐照硬化，这表现为辐照样品强度的增加和应变爆发的减少。这种变形行为的变化表明了辐射引起的缺陷对位错动力学的影响。氦注入导致表面台阶的形成，并且如纳米压痕图所示，导致硬度局部增加，凸显了氦对机械性能的显着影响。显微组织检查揭示了钢的回火马氏体结构，并指出了 MC 和 MX 析出物在调节辐照效果中的重要性。值得注意的是，K-RAFM 钢的辐照硬化程度降低，这可归因于较高比例的 MX 沉淀物作为点缺陷的有效捕获位点。了解微观结构特征如何影响 K-RAFM 钢的机械性能有助于指导开发定制材料，以提高核环境中的抗辐射能力。