定向凝固T91钢热疲劳行为的模拟与实验研究

项目名称： 定向凝固T91钢热疲劳行为的模拟与实验研究

项目编号： No.51301169

项目类型： 青年科学基金项目

立项/批准年度： 2014

项目学科： 一般工业技术

项目作者： 史子木

作者单位： 中国科学院合肥物质科学研究院

项目金额： 25万元

中文摘要： T91耐热钢是未来核裂变反应堆系统最有可能应用的关键结构材料之一，其热疲劳性能的优劣将直接影响到未来的服役行为及寿命。本课题针对晶体取向及晶界结构对金属材料热疲劳性能的重要影响，拟通过定向凝固的方法，生长出形貌及尺寸不同的晶体组织；通过系统考察晶体取向、界面形貌、晶粒尺寸和枝晶间距等对材料力学性能的贡献，建立材料组织参数与力学行为及疲劳寿命之间的内在联系；通过微观组织观察及疲劳过程界面组织演化规律的分析，揭示定向凝固T91钢的应变疲劳损伤与破坏的物理机制；结合实验结果与模拟分析，给出组织参量与疲劳寿命的解析表达式。为T91钢在核裂变堆中的应用提供设计依据。

中文关键词： T91钢；定向凝固；柱状晶；热疲劳性能；氧化物弥散强化

英文摘要： T91 heat-resistant steel is one of the key structural materials that will be most probably used in future nuclear fission reactor system, and the thermal fatigue properties of it will determine its performance and life. Since the grain orientation and boundary structure have extremely important influences on the thermal fatigue properties of metal materials, the present proposal is to obtain crystal grains with varied morphologies and dimentions through directional solidification; to correlate the structural parameters with the mechanical behavior and thermal fatigue life through systematically analyzing the contributions of grain orientation, morphology, size and dendrite spacing to the mechanical properties; to disclose the physical mechanisms of fatigue damage and failure of directionally solidified T91 steel through investigation into the evolution of microstructres and interfaces during the fatigue; to give analytical equation of microstructure parameters and fatigue life based on the experimental results and the simulation analysis.It is expected that the present study would give design references for the future application of T91 steel in nuclear fission system.

英文关键词： T91 steel；Directional solidification；colunmar grain；Thermal fatigue；ODS