Ion irradiation provides a promising substitute to neutron tests for investigating the effects of radiation on materials for fission and fusion reactor plants. Here we show proton irradiation can quantitatively reproduce precipitation that leads to embrittlement in reactor pressure vessel steels, at dose rates ${10}^4$ times greater than experienced in fission reactor operation. Small-angle neutron scattering (SANS) is used to characterize precipitate size distributions in copper-containing steels irradiated to average doses of $\simeq 7$ mdpa with 5 MeV protons. Comparing our results with the literature on reactor pressure vessel steels containing $\ge 1$ at.% nickel, we find a power-law scaling of dose with exponent 0.25–0.30 accounts for the effects of dose rate on precipitate volume fraction over 6 orders of magnitude in dose rate. In conjunction with dose rate, carbon is identified as performing a leading role in determining precipitate sizes, adding to the known effects of nickel, manganese and irradiation temperature. We discuss the composition of precipitates inferred from SANS, taking previous atom probe tomography studies into consideration.

离子辐射为研究辐射对裂变和聚变反应堆工厂材料的影响提供了一种有希望的替代中子测试的方法。在这里，我们展示了质子辐照可以在剂量率下定量再现导致反应堆压力容器钢脆化的沉淀${10}^4$比在裂变反应堆操作中所经历的还要多倍。小角中子散射 (SANS) 用于表征辐照平均剂量为$\simeq 7$ mdpa 具有 5 MeV 质子。将我们的结果与有关反应堆压力容器钢的文献进行比较$\ge 1$ at.% 镍，我们发现剂量率指数为 0.25-0.30 的幂律比例解释了剂量率对超过 6 个数量级的剂量率的沉淀体积分数的影响。结合剂量率，碳被确定在确定沉淀物尺寸方面起主导作用，增加了镍、锰和辐照温度的已知影响。我们讨论了从 SANS 推断出的沉淀物的组成，同时考虑了以前的原子探针断层扫描研究。