关键词：管道；钢；断裂强度；缺口冲击试验
摘 要：Fracture toughness and fatigue properties of pipeline steels play a critical role in developing advanced high-pressure hydrogen infrastructure for alternative fuel pipelines program. The reliability of structure components, particularly resistance to damage and failure in the intended service environment, is highly dependent on the selected materials. An effective surveillance program is also necessary to monitor the material degradation during the course of service. Steels have been proven to be desirable for hydrogen infrastructure. However, hydrogen embrittlement is an important factor that limits steel performance under high-pressure hydrogen conditions. In order to reach the above goal, we have proposed an innovative technology, based on spiral notch torsion test (SNTT) methodology, to effectively investigate the material performance of X52 pipeline steel. The SNTT approach was successfully demonstrated and extended to X52 steels during the performance period. In addition to single notch front geometry, the crack growth behavior of the SNTT process has been effectively established using an integrated experimental, numerical and analytical approach. The results indicate that the proposed protocol not only provides significant advance in understanding the compliance evolution of the SNTT specimen, but also can be readily utilized to assist future development of hydrogen infrastructures. In FY2011, an extensive study was performed to characterize the fracture toughness degradation of AISI 4340 high-strength steel exposed to high-pressure hydrogen using in situ spiral notch torsion tests. This effort included equipment setup and calibration, sample design and fabrication, finite element simulation of the specimen fracture, and fractographic characterization using advanced microscopic techniques. The detailed description of the results is summarized in by Wang (Wang 2011).