The improved crack nucleation resistance of shot-peened materials has been usually studied from the point of view of the residual stresses. However, experimental limitations have made difficult to quantify strain localization during further deformation. In this study, we have used high-resolution digital image correlation (HRDIC) and electron backscatter diffraction (EBSD) in a large area covering shot-peened material and bulk to study quantitatively the strain distribution at the submicron scale. We found that, at the earlier deformation steps (e < 2.5%), the slip intensity and distribution at the shot-peened region differ from that observed at the bulk. In the former, well-spaced, sharp and homogeneously distributed slip bands are observed. On the other hand, in the shot-peened region, slip is less evident, and a more homogeneous diffuse deformation is observed along the majority of the grains. However, this region also contains a small number of slip bands that accumulate high strains, mainly along Σ3 annealing twin boundaries. Additionally, the border between both regions, at a depth with no residual stress, present the minimum strain values. During further deformation (e > 2.5%), the strain distributions become similar along the material simultaneously to the residual stresses relaxation. A further analysis of the HRDIC maps allowed for the first time to quantify strain heterogeneity. This study reveals the importance of the local stress state and the strain history on the strain localization during loading of peened materials.

通常从残余应力的角度研究喷丸材料提高的抗裂纹成核能力。然而，实验限制使得在进一步变形期间难以量化应变局部化。在这项研究中，我们在大面积覆盖喷丸材料和体块中使用高分辨率数字图像相关 (HRDIC) 和电子背散射衍射 (EBSD) 来定量研究亚微米尺度的应变分布。我们发现，在较早的变形步骤 (e < 2.5%) 中，喷丸强化区域的滑移强度和分布与块体观察到的不同。在前者中，观察到间隔良好、尖锐且均匀分布的滑移带。另一方面，在喷丸区域，滑移不太明显，沿大部分晶粒观察到更均匀的扩散变形。然而，该区域也包含少量积累高应变的滑移带，主要沿 Σ3 退火孪晶边界。此外，在没有残余应力的深度处，两个区域之间的边界呈现最小应变值。在进一步变形 (e > 2.5%) 期间，沿材料的应变分布与残余应力松弛同时变得相似。对 HRDIC 图的进一步分析首次允许量化菌株异质性。这项研究揭示了局部应力状态和应变历史对喷丸材料加载过程中应变局部化的重要性。该区域还包含少量积累高应变的滑移带，主要沿 Σ3 退火孪晶边界。此外，在没有残余应力的深度处，两个区域之间的边界呈现最小应变值。在进一步变形 (e > 2.5%) 期间，沿材料的应变分布与残余应力松弛同时变得相似。对 HRDIC 图的进一步分析首次允许量化菌株异质性。这项研究揭示了局部应力状态和应变历史对喷丸材料加载过程中应变局部化的重要性。该区域还包含少量积累高应变的滑移带，主要沿 Σ3 退火孪晶边界。此外，在没有残余应力的深度处，两个区域之间的边界呈现最小应变值。在进一步变形 (e > 2.5%) 期间，沿材料的应变分布与残余应力松弛同时变得相似。对 HRDIC 图的进一步分析首次允许量化菌株异质性。这项研究揭示了局部应力状态和应变历史对喷丸材料加载过程中应变局部化的重要性。在进一步变形 (e > 2.5%) 期间，沿材料的应变分布与残余应力松弛同时变得相似。对 HRDIC 图的进一步分析首次允许量化菌株异质性。这项研究揭示了局部应力状态和应变历史对喷丸材料加载过程中应变局部化的重要性。在进一步变形 (e > 2.5%) 期间，沿材料的应变分布与残余应力松弛同时变得相似。对 HRDIC 图的进一步分析首次允许量化菌株异质性。这项研究揭示了局部应力状态和应变历史对喷丸材料加载过程中应变局部化的重要性。