The α′ precipitation in Fe-Cr alloys under electron, neutron and ion irradiations is modelled by cluster dynamics and atomistic kinetic Monte Carlo simulations. The former method provides the evolution of the density of point defect sinks. This density is then introduced in the Monte Carlo which models the diffusion of point defects and atoms. By comparison with previous studies, this provides a better description of the evolution of point defect concentrations and therefore of the balance between two competing irradiation effects: the acceleration of diffusion and the ballistic mixing. The prediction of the model is in agreement with existing atomic-scale experiments already reported after electron, ion and neutron irradiations or obtained for the present study. Irradiation is found to accelerate the precipitation by orders of magnitude, except for the case of ion irradiation at high doses rates, where the simulations predict a ballistic dissolution of α′ precipitates. According to our model, this dissolution is mainly due to a high sink density, which reduces the concentrations of point defects and limits the acceleration of diffusion. This effect may be reinforced by carbon contamination, which reduces the mobility of point defects.

通过团簇动力学和原子动力学蒙特卡洛模拟，模拟了铁，铬合金在电子，中子和离子辐照下的α'析出。前一种方法提供了点缺陷阱密度的演变。然后将这种密度引入蒙特卡洛模型，该模型对点缺陷和原子的扩散进行建模。通过与以前的研究相比较，这可以更好地描述点缺陷浓度的变化，从而更好地描述两种竞争性辐照效应之间的平衡：扩散的加速和弹道的混合。该模型的预测与在电子，离子和中子辐照后已经报道或为本研究获得的现有原子级实验一致。发现辐照可加速降水数量级，除了在高剂量率下进行离子辐照的情况外，模拟预测α'沉淀物的弹道溶解。根据我们的模型，这种溶解主要是由于高的沉密度，这降低了点缺陷的浓度并限制了扩散的加速。碳污染可能会增强这种效果，碳污染会降低点缺陷的迁移率。