Predictive assessment of hydrogen diffusion and segregation in high-strength steels: an ICME approach**

氢脆（HE）是一种在氢存在下使材料易于过早失效的过程，是紧固件和航空航天工业面临的直接挑战，其中可靠耐用的高强度钢（HSS）至关重要。 尽管HE的历史悠久，但对HSS中微观结构处的氢扩散和偏析的机理细节仍然知之甚少，使得不可能准确评估HE，从而阻碍了新HSS的开发和部署。该项目建议使用综合方法，融合严格的计算建模和实验之间的协同作用，以定量定义微观结构在控制氢的热力学和动力学中的作用，以及随后对HSS中HE的影响。 将采用结合机器学习的多尺度建模方案来识别微观结构中氢偏析和动力学的关键纳米级机制，同时将微观信息转化为大规模数值模拟的宏观参数。将开发新的高分辨率显微成像技术，以可视化小规模的缺陷结构，并将设计和执行目标实验，以验证和校准理论和计算模型。 该项目将进一步涉及标准的工业HE筛选测试，将研究直接置于工业应用的背景下。 该项目将率先开发集成计算材料工程（ICME）方法，为行业提供创新解决方案，以优化其现有的冶金工艺，减轻HE损伤，并加速下一代抗HE HSS的开发。 由于HSS具有很大的通用性和显著的轻量化优势，该项目符合NSERC战略计划的先进制造目标领域，主题是轻量化材料和技术。此外，它将满足加拿大对ICME能力的迫切需要，并将培训新一代工程师，使他们具备综合ICME与工业实践和标准的全面知识基础。****************

Hydrogen embrittlement (HE), a process by which a material is rendered prone to premature failure in the presence of hydrogen, is an immediate challenge to fastener and aerospace industries where reliable and durable high-strength steel (HSS) is of critical importance. Despite a long history of HE, the mechanistic details of hydrogen diffusion and segregation at microstructures in HSS remain poorly understood, rendering accurate assessments of HE not possible and thus hindering the development and deployment of new HSS. This project proposes to use an integrated approach, fusing synergy between rigorous computational modeling and experimentation to quantitatively define the role of microstructures in controlling thermodynamics and kinetics of hydrogen, and the subsequent implication to HE in HSS. A multiscale modeling scheme combining machine learning will be employed to identify key nanoscale mechanisms of hydrogen segregation and kinetics at microstructures, and meanwhile to translate microscopic information into macroscopic parameters for large-scale numerical simulations. Novel high-resolution microscopy imaging techniques will be developed to visualize small-scale defect structures, and target experiments will be designed and performed to validate and calibrate theoretical and computational models. The project will further involve standard industrial HE screening tests to put the research directly in the context of industrial applications. The project will pioneer the development of an integrated computational materials engineering (ICME) approach to provide innovative solutions for the industry to optimize their existing metallurgical processes, mitigate HE damage, and accelerate the development of next-generation HE-resistant HSS. With HSS being of great versatility and significant advantages for lightweighting, this project fits the NSERC Strategic Program's Target Area of Advanced Manufacturing, on the topic of Lightweight Materials and Technologies. Moreover, it will address Canada's imperative need of ICME competency, and will train the new generation of engineers to equip them with a comprehensive knowledge base combining ICME and industrial practices and standards. ****************