Henry Moseley X-ray Imaging Facility, School of Materials, The University of Manchester, Manchester, M13 9PL, UK.
School of Materials, The University of Manchester, Manchester, M13 9PL, UK.
Sci Rep. 2017 Aug 4;7(1):7332. doi: 10.1038/s41598-017-06976-5.
Creep cavitation in an ex-service nuclear steam header Type 316 stainless steel sample is investigated through a multiscale tomography workflow spanning eight orders of magnitude, combining X-ray computed tomography (CT), plasma focused ion beam (FIB) scanning electron microscope (SEM) imaging and scanning transmission electron microscope (STEM) tomography. Guided by microscale X-ray CT, nanoscale X-ray CT is used to investigate the size and morphology of cavities at a triple point of grain boundaries. In order to understand the factors affecting the extent of cavitation, the orientation and crystallographic misorientation of each boundary is characterised using electron backscatter diffraction (EBSD). Additionally, in order to better understand boundary phase growth, the chemistry of a single boundary and its associated secondary phase precipitates is probed through STEM energy dispersive X-ray (EDX) tomography. The difference in cavitation of the three grain boundaries investigated suggests that the orientation of grain boundaries with respect to the direction of principal stress is important in the promotion of cavity formation.
通过跨越八个数量级的多尺度断层扫描工作流程，对退役核蒸汽集管 316 型不锈钢样品中的爬行动带空化进行了研究，该工作流程结合了 X 射线计算机断层扫描（CT）、等离子体聚焦离子束（FIB）扫描电子显微镜（SEM）成像和扫描透射电子显微镜（STEM）断层扫描。在微尺度 X 射线 CT 的指导下，纳米尺度 X 射线 CT 用于研究在晶界三叉点处空洞的大小和形态。为了了解影响空化程度的因素，使用电子背散射衍射（EBSD）对每个晶界的方向和晶体取向错配进行了表征。此外，为了更好地了解边界相的生长，通过 STEM 能量色散 X 射线（EDX）断层扫描探测了单个边界及其相关二次相析出物的化学性质。研究的三个晶界的空化差异表明，晶界相对于主应力方向的取向对于促进空穴形成很重要。
