The changes in the microstructure of 3.5 MeV proton irradiated T91 Ferritic-Martensitic steel samples with dose have been evaluated using detailed X-ray diffraction line profile analysis of the data collected using both laboratory and the synchrotron source. Different line profile analysis techniques like Williamson-Hall, modified Rietveld method and convolutional multiple whole profile fitting have been applied to evaluate the microstructural parameters such as domain size, microstrain, dislocation density and the character of the dislocation from both the data. The coherent domain size decreases and the corresponding microstrain increases at the first dose of irradiation. With further irradiation, these parameters show a slight recovery and eventually tend towards saturation with increasing dose. The dislocation density follows similar trend as the microstrain showing saturation at higher doses of irradiation in both the XRD data. However, a systematic change in the character of the dislocation from screw-type to edge-type could be ascertained only from the data obtained using synchrotron source. The Vickers microhardness of the samples is found to increase continuously with increasing irradiation dose supporting the observed change in the dislocation character from screw-type (glissile) to edge-type (sessile). Both EBSD and TEM analysis of the unirradiated and irradiated samples have supported the results obtained from the XRD analysis.

对3.5 MeV质子辐照的T91铁素体-马氏体钢样品的微观结构随剂量的变化已使用实验室和同步辐射源收集的数据进行了详细的X射线衍射线轮廓分析后进行了评估。已应用了不同的线轮廓分析技术（例如Williamson-Hall，改进的Rietveld方法和卷积多重整体轮廓拟合）来评估微观结构参数，例如畴尺寸，微应变，位错密度和这两个数据的位错特征。在辐射的第一剂量下，相干畴尺寸减小并且相应的微应变增大。随着进一步的照射，这些参数显示出轻微的恢复，并最终随着剂量的增加而趋于饱和。位错密度遵循相似的趋势，因为在两个XRD数据中微应变在较高剂量的辐照下都显示出饱和。然而，仅从使用同步加速器源获得的数据中可以确定从螺旋型到边缘型的位错特征的系统变化。发现样品的维氏显微硬度随着辐照剂量的增加而连续增加，这支持了观察到的位错特征从螺旋型（易碎性）到边缘型（无梗性）的变化。未辐照和辐照样品的EBSD和TEM分析均支持从XRD分析获得的结果。仅从使用同步加速器源获得的数据中可以确定从螺旋型到边缘型的位错特征的系统变化。发现样品的维氏显微硬度随着辐照剂量的增加而连续增加，这支持了观察到的位错特征从螺旋型（易碎性）到边缘型（无梗性）的变化。未辐照和辐照样品的EBSD和TEM分析均支持从XRD分析获得的结果。仅从使用同步加速器源获得的数据中可以确定从螺旋型到边缘型的位错特征的系统变化。发现样品的维氏显微硬度随着辐照剂量的增加而连续增加，这支持了观察到的位错特征从螺旋型（易碎性）到边缘型（无梗性）的变化。未辐照和辐照样品的EBSD和TEM分析均支持从XRD分析获得的结果。