A directionally solidified Ni-based superalloy DS200 is investigated under low (750 °C) and high temperature (900 °C) transverse creep. In-situ creep tests with strain measurements are performed to capture creep strain evolution in the individual crystallographic grains. Moreover, the microstructure configurations that promote damage nucleation are identified as a function of the loading condition. High angle grain boundaries are the preferred sites for crack nucleation under all investigated loading conditions. However, grain boundary configurations promoting crack nucleation are observed to significantly differ as a function of the loading conditions. Such observations are discussed in view of creep behavior and damage processes.

研究了低温（750°C）和高温（900°C）横向蠕变下的定向凝固镍基高温合金DS200。使用应变测量进行原位蠕变测试以捕获单个晶粒中的蠕变应变演变。此外，促进损伤成核的微观结构配置被确定为加载条件的函数。在所有研究的加载条件下，大角度晶界是裂纹成核的首选​​位置。然而，观察到促进裂纹成核的晶界配置作为加载条件的函数存在显着差异。考虑到蠕变行为和损坏过程来讨论这些观察结果。