Fast efficient modelling of hydride reorientation

氢化物重定向的快速高效建模

• 批准号: 2296164
• 金额: --
• 依托单位: Imperial College London
• 依托单位国家: 英国
• 项目类别: Studentship
• 财政年份: 2019
• 资助国家: 英国
• 起止时间: 2019 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=studentship-2296164
• 关键词: Fast; efficient; modelling; hydride; reorientation

A mechanistic understanding of hydrogen diffusion and hydride precipitation underpins the prediction of delayed hydride cracking (DHC) in zirconium alloy nuclear fuel cladding. DHC presents a problem to service life of nuclear fuel pins and integrity of pins in waste storage. This project builds upon a study by a previous student to use analytical stress fields, in combination with discrete dislocations, to model a millimetre scale area but with single micron accuracy, including grain orientation effects, but in seconds rather than hours (as per state-of-the-art phase field models). The new modelling approach is being examined by Rolls-Royce for incorporation into their research strategy and has gained significant interest in the US via the Department of Energy (DOE) and Electric Power Research Institute (EPRI). Whilst showing potential, the model captures only some of the relevant phenomena. This project, will couple to the existing framework, other crucial aspects of DHC, including grain boundary compatibility stresses, intergranular versus transgranular hydride precipitation; further enhancement of the coupling of atomic hydrogen diffusion to microscale hydride precipitation (to enable cooling effects to be modelled, especially thermal cycles known as ratchetting) and finally to develop visualization/image analysis tools to characterize the resultant microstructures for reorientation of hydrides producing a probabilistic model that can be used by industry.

氢扩散和氢化物沉淀的机理理解支持锆合金核燃料包壳中延迟氢化物开裂（DHC）的预测。DHC对核燃料棒的使用寿命和废料贮存中棒的完整性提出了问题。该项目建立在以前的学生使用分析应力场的研究基础上，结合离散位错，以毫米级面积建模，但具有单微米精度，包括晶粒取向效应，但在几秒钟而不是几小时内（根据最先进的相场模型）。罗尔斯·罗伊斯公司正在研究将新的建模方法纳入其研究战略，并通过能源部（DOE）和电力研究所（EPRI）在美国引起了极大的兴趣。虽然显示了潜力，但该模型只捕捉了一些相关现象。这个项目，将耦合到现有的框架，DHC的其他关键方面，包括晶界相容性应力，晶间与穿晶氢化物沉淀;进一步增强原子氢扩散与微尺度氢化物沉淀的耦合（为了能够模拟冷却效果，特别是称为棘轮效应的热循环），最后，图像分析工具，以表征所得的微结构，用于重新定向微结构，产生可由工业使用的概率模型。