Mechanistic Understanding of Creep-Fatigue led Degradation of Electron Bean Welded ODS Steels in Tension and Compression Hold

Welding of thick steel plates are essential requirement of future nuclear power plant components. The welding processes generate residual stresses, which can have negative effects on the service life of welded components or structures. When present in addition to external loadings, residual stresses can contribute to premature component failure and can affect crack initiation and growth. Due to extremely high temperature in future nuclear power plants, instability of the residual stress in complex creep-fatigue loading environment is of significant concern for the structural integrity of welded components. In this experiment, we will use Electron Beam Welded (EBM) and Gas Tungsten Arc Welded (GTAW) Ferritic- Martensitic Steel and AISI 316(L) 30mm thick welds of recently funded pilot project SiMeW (Simulation and Measurement of Welds) of The Joint Programme on Nuclear Materials of the European Energy Research Alliance (EERA-JPNM). The experiment will lead to development of an empirical model of residual stress stability in tension and compression creep holds at extremely high temperature 700℃ which will be used in Gen-IV nuclear reactors.

厚钢板焊接是未来核电站构件制备不可或缺的核心工序。焊接过程会产生残余应力，该类应力会对焊接构件或结构的服役寿命造成不利影响。当残余应力与外加载荷共同作用时，会加速构件过早失效，并影响裂纹的萌生与扩展过程。由于未来核电站的工作温度极高，复杂蠕变-疲劳载荷环境下残余应力的不稳定性，已成为影响焊接构件结构完整性的重大关注点。本实验将采用欧洲能源研究联盟核材料联合计划（European Energy Research Alliance Joint Programme on Nuclear Materials, EERA-JPNM）新近资助的试点项目SiMeW（焊缝模拟与测量，Simulation and Measurement of Welds）中的30mm厚铁素体-马氏体钢与AISI 316(L)钢的电子束焊接（Electron Beam Welded, EBM）及钨极氩弧焊接（Gas Tungsten Arc Welded, GTAW）焊缝试件。本实验将构建700℃极端高温环境下拉压蠕变保载阶段的残余应力稳定性经验模型，该模型将应用于第四代核反应堆中。