Irradiation

辐照诱导析出相/晶界偏析是不锈钢辐照降解的主要原因之一。例如，细小的沉淀物会导致辐照诱发硬化。本研究利用三维原子探针研究了在轻水反应堆运行温度下每原子20位移以上辐照剂量的不锈钢在商业压水反应堆燃料包壳板中的辐照情况。观察到较高的Ni-Si相密度，比透射电镜观察到的Frank环高一个数量级。详细分析了析出相的尺寸、数量、密度和化学成分等形貌，并利用orowan模型对析出相的硬化程度进行了估计。发现Ni-Si析出物对辐照硬化有重要作用。

Irradiation-induced precipitates/grain boundary segregation are one of the main origins for irradiation-induced degradation of a stainless steel. For instance, fine precipitates causes irradiation-induced hardening. This study investigated a stainless steel irradiated to a dose of over twenty displacement per atom at the temperature of a light water reactor operation in the fuel wrapper plates of a commercial pressurized water reactor by using three-dimensional atom probe. A high number density of Ni-Si precipitates was observed, which is one order of magnitude higher than that of Frank loops observed by transmission electron microscope. The morphology of the precipitate, such as size, number density and chemical composition, were analyzed in detail, then the hardening due to the precipitates was estimated by using Orowan-model. It is found that the Ni-Si precipitates have an important contribution to irradiation-hardening.