涉氢环境及其对高温合金的影响:评述--面向航空发动机潜在应用

Hydrogen-related environment and its effect on superalloys:a review--targeted for potential aero-engine application

随着“双碳”目标的提出,氢作为绿色清洁能源成为未来航空业发展的重要趋势,近年来氢燃料航空发动机备受关注。高温合金是当前燃气涡轮发动机热端部件中应用最广泛的材料,本文综述现有其他领域涉氢环境对合金的影响,为未来氢燃料航空发动机用高温合金研制和应用提供参考。对内/外氢环境的引入、渗(充)氢方法、氢浓度/氢分布特征及氢稳定存在温度的测量、氢对拉伸、蠕变/持久和疲劳性能的影响以及氢脆的断裂机理进行分述,总结不同成分、制备工艺、原始组织状态、合金化程度以及不同应用领域高温合金在涉氢环境下的力学性能退化因素。结果表明,外氢环境下比内氢环境下力学性能下降更快;合金化程度更高的高温合金氢脆更明显,而高温氢环境下合金性能损伤(蠕变/持久、疲劳和拉伸)倾向较室温明显降低。就燃氢涡轮动力用高温合金在涉氢环境下的力学性能评价及适氢环境高温合金的研制进行展望。燃氢涡轮航空发动机可能面临的涉氢工作环境包括:液氢存储的低温氢环境;用于通道冷却的氢环境;经过气体压缩的高温高压氢环境;以及燃烧产物-高温水蒸气(高温潮湿)环境的影响。重点应关注氢在高温合金中的扩散和渗透、高温合金在高压氢环境下的脆性和腐蚀、高温潮湿环境下氧化和腐蚀行为以及上述多重耦合环境下合金和涂层的退化和防护机制。针对燃氢涡轮发动机工作环境,需要搭建近服役条件的高温合金燃氢环境实验装置,开展燃氢环境对高温合金及零部件的影响研究,建立现役叶片和盘件等热端部件关键用材在涉氢环境中的力学性能数据库和相关标准,并在此基础上适时研发适用于燃氢环境使用的高温结构材料,为氢燃料燃气涡轮航空发动机的应用提供支持。

With the proposal of the“dual carbon”goals,using hydrogen as zero-carbon alternative fuel has become an important trend of the aviation industry in the future.In recent years,the hydrogen-fueled aero-engines have garnered significant attention.Superalloys are the most widely used materials in the hot section components of gas turbine engines.The purpose of this review is to provide reference for the research and development of superalloys for hydrogen-fueled aero-engines future use by understanding the effects of hydrogen-related environment on superalloys currently across various fields.Internal/external hydrogen environments,hydrogen permeation(charging)methods,measurement of hydrogen concentration/distribution or stable existence temperature,the influence of hydrogen on tensile strength,the impact of hydrogen on creep/stress rupture and fatigue properties,and the fracture mechanism of hydrogen embrittlement are described.The degradation factors of mechanical properties of superalloys with different composition,manufacturing process,original microstructure,alloying degree and different application fields under hydrogen-related environment are summarized.In general,mechanical properties tests in the external hydrogen environment exhibit more significant hydrogen-assisted mechanical degradations than that in internal hydrogen environments.Superalloys with higher alloying degree exhibit more pronounced hydrogen embrittlement,while the tendency of properties decrease(creep/rupture,fatigue and tensile)in hydrogen at elevated temperature is much less than that at room temperature.The prospects for the mechanical performance evaluation of current superalloys in hydrogen-related environments for hydrogen-fueled gas turbine and the development of new alloys suitable for hydrogen environments are provided.Hydrogen-fueled gas turbine aero-engines may encounter cryogenic temperature hydrogen environment for liquid hydrogen storage,hydrogen environment for cooling,high-temperature/high-pressure hydrogen environment for gas compression,and the impact of combustion products-water vapor(humid)at elevated temperature.Diffusion or permeation of hydrogen in superalloys,the embrittlement and corrosion of alloys in high-pressure hydrogen environments,oxidation and corrosion behavior in high-temperature humid environments,as well as the degradation and protection mechanism for alloys and coatings in the aforementioned multiple coupling environments shall be concerned.It is necessary to establish hydrogen combustion environment experimental facility that closely simulates service conditions to conduct research on the impact of hydrogen-related environment on superalloys and their components.It is also essential to establish a mechanical performance database and standards for currently used key materials in hot section components such as turbine blades and disks for hydrogen related environments,and properly develop new high-temperature structural materials suitable for hydrogen combustion conditions,which will provide support for the application of hydrogen fueled gas turbine aero-engines.