Principles for the design of components exposed to pressurized hydrogen taking into account material-related damage mechanisms

暴露于加压氢气的部件的设计原则，考虑到与材料相关的损坏机制

• 批准号: 271741688
• 负责人: Professor Dr.-Ing. Tobias Melz
• 金额: --
• 依托单位: Fachgebiet und Institut für Werkstoffkunde
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2015
• 资助国家: 德国
• 起止时间: 2014-12-31 至 2019-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/271741688?language=en
• 关键词: Principles; design; components; exposed; pressurized

Scarcities of resources as well as latest developments in the international automotive industry underline a growing importance of hydrogen as a future energy source and fuel.Its application requires the development and qualification of new materials and consideration of the influence of hydrogen in the design process of components exposed to hydrogen.Basic characterisations of the material behaviour of steels under exposure to pressurized hydrogen or electrolytic loading have been subject of numerous studies. The planned research project focuses on the design of cyclically loaded components exposed to pressurized hydrogen taking into account material properties. Emphasis will be put on the application of local strain concepts as well as the transfer concept for cyclic data, the highly stressed material volume. Last mentioned concept will be enhanced regarding a hydrogen permeation volume in dependence of the strain amplitude and local strain distribution.The local concept bases on the assumption that local processes and material behaviour at critical locations are determinant for the initiation of fatigue cracks and therefore fatigue life, irrespective of the complexity of component geometry.While minor influences of stress gradients and testing frequencies are assumed for the application in air, they have to be expected for hydrogen exposure.In order to quantify influencing parameters strain- and force-controlled fatigue tests will be carried out in air and under pressurized hydrogen at 50 bar at different testing frequencies with notched and unnotched specimens.The influence of static and dynamic mechanical loading on the diffusion and trapping behaviour at selected load levels will be characterised under strain- and force-control in electrochemical permeation tests and be compared to the unloaded condition. Moreover, the determination of the permeation current density over time allows an assessment of hydrogen activity in dependence of time and applied load.In order to gain information regarding the potential threat of hydrogen embrittlement due the effective content of hydrogen TDS/hot carrier gas extraction measurements will be carried out after completion of the fatigue and permeation tests for each strain and force level.Extensive significance of the research results is ensured by the selection of two steels with austenitic and ferritic microstructure that reveal significant differences in their trapping and diffusion behaviour.Based on the research results application limitations of the local concept as well as the transfer concept of the highly stressed material volume for the design of components exposed to hydrogen will be pointed out and essential adaptations of the concepts as well as the experimental parameter determination be deduced.

资源的稀缺以及国际汽车工业的最新发展突显了氢作为未来能源和燃料的日益重要。氢的应用需要新材料的开发和鉴定，并在暴露于氢的部件的设计过程中考虑氢的影响。钢在暴露于加压氢或电解负载下的材料行为的基本特征已经成为众多研究的主题。计划中的研究项目侧重于设计暴露于加压氢气的循环加载组件，同时考虑材料特性。重点将放在局部应变概念以及循环数据（高应力材料体积）的传递概念的应用上。最后提到的概念将根据应变幅度和局部应变分布增强氢渗透体积。局部概念基于这样的假设：关键位置的局部过程和材料行为决定了疲劳裂纹的萌生，从而决定了疲劳寿命，而与部件几何形状的复杂性无关。虽然假定在空气中的应用中应力梯度和测试频率的影响较小，但对于氢来说，必须预期到这些影响 为了量化影响参数，应变和力控制的疲劳试验将在空气中和在 50 bar 的加压氢气下以不同的测试频率对有缺口和无缺口的样品进行。在选定的负载水平下，静态和动态机械载荷对扩散和捕获行为的影响将在电化学渗透测试中的应变和力控制下进行表征并进行比较 到卸载状态。此外，随着时间的推移渗透电流密度的测定可以评估氢活性随时间和施加载荷的变化。为了获得有关氢脆化潜在威胁的信息，在完成每个应变和力水平的疲劳和渗透测试后，将进行有效的氢含量TDS/热载气提取测量。通过选择两种奥氏体钢和奥氏体钢，确保了研究结果的广泛意义。 铁素体微观结构揭示了它们的捕获和扩散行为的显着差异。根据研究结果，将指出局部概念以及高应力材料体积传递概念在暴露于氢的部件设计中的应用局限性，并推导出这些概念的基本适应以及实验参数的确定。