The influence of irradiation defect dispersions on plastic strain spreading is investigated by means of three-dimensional dislocation dynamics (DD) simulations, accounting for thermally activated slip and cross-slip mechanisms in Fe-2.5%Cr grains. The defect-induced evolutions of the effective screw dislocation mobility are evaluated by means of statistical comparisons, for various defect number density and defect size cases. Each comparison is systematically associated with a quantitative Defect-Induced Apparent Straining Temperature shift (or «ΔDIAT»), calculated without any adjustable parameters. In the investigated cases, the ΔDIAT level associated with a given defect dispersion closely replicates the measured ductile to brittle transition temperature shift (ΔDBTT) due to the same, actual defect dispersion. The results are further analyzed in terms of dislocation-based plasticity mechanisms and their possible relations with the dose-dependent changes of the ductile to brittle transition temperature.

通过三维位错动力学（DD）模拟研究了辐照缺陷分散体对塑性应变扩展的影响，其中考虑了Fe-2.5％Cr晶粒中的热活化滑动和交叉滑动机制。由缺陷引起的有效演化对于各种缺陷数量密度和缺陷尺寸情况，通过统计比较来评估螺钉脱位的迁移率。每个比较都与定量的缺陷引起的表观应变温度偏移（或“ΔDIAT”）系统地关联，该变化无需任何可调整的参数即可计算。在研究的情况下，由于相同的实际缺陷分散，与给定缺陷分散相关的ΔDIAT水平紧密地复制了所测得的韧性至脆性转变温度变化（ΔDBTT）。进一步分析了基于位错的可塑性机制及其与韧性到脆性转变温度的剂量依赖性变化的可能关系。