航空学报 > 2025, Vol. 46 Issue (15): 431439-431439   doi: 10.7527/S1000-6893.2024.31439

氢对TC4ELI钛合金焊接接头组织和性能的影响

杨日明1,2, 申秀丽1,2, 董少静1,2()   

  1. 1.北京航空航天大学 能源与动力工程学院,北京 100191
    2.先进航空发动机协同创新中心,北京 100191
  • 收稿日期:2024-10-23 修回日期:2024-12-23 接受日期:2025-02-05 出版日期:2025-02-20 发布日期:2025-02-18
  • 通讯作者: 董少静 E-mail:dongshaojing@buaa.edu.cn
  • 基金资助:
    中央高校基本科研业务费专项资金(501XTCX2023146001)

Influence of hydrogen on microstructure and mechanical properties of TC4ELI titanium alloy welded joints

Riming YANG1,2, Xiuli SHEN1,2, Shaojing DONG1,2()   

  1. 1.School of Energy and Power Engineering,Beijing University of Aeronautics and Astronautics,Beijing 100191,China
    2.Collaborative Innovation Center for Advanced Aero-Engine,Beijing 100191,China
  • Received:2024-10-23 Revised:2024-12-23 Accepted:2025-02-05 Online:2025-02-20 Published:2025-02-18
  • Contact: Shaojing DONG E-mail:dongshaojing@buaa.edu.cn
  • Supported by:
    Fundamental Research Funds for the Central Universities(501XTCX2023146001)

摘要:

TC4ELI钛合金在氢燃料发动机上应用前景巨大,但涉氢部件焊接结构存在氢损伤风险。通过电子束焊接和高温气相充氢得到了充氢0.2%的焊接TC4ELI拉伸、疲劳和纳米压痕试验件,结合X射线衍射和二次离子质谱等微观表征,开展了纳米压痕和低周疲劳等力学试验,深入研究了氢对TC4ELI焊接接头微观组织和力学性能的影响。结果表明,充氢促进TC4ELI焊接接头各微区α→β相变,析出δ氢化物,且焊缝区内析出的氢化物较多,对应的弹性模量和硬度下降程度最大,焊接接头组织和性能趋于均匀化。TC4ELI焊接件充氢后弹性模量和断裂应变显著降低,氢化物导致断裂模式由穿晶韧窝断裂转变为沿晶脆性断裂。充氢TC4ELI焊接件在低应力水平下因应力诱导氢化物开裂,低周疲劳寿命显著降低,在高应力水平下因氢致局部塑性,表现出更好的抗疲劳性能。

关键词: TC4ELI钛合金, 电子束焊接, 氢损伤, 微观组织, 力学性能, 纳米压痕

Abstract:

TC4ELI titanium alloy has a great application prospect in hydrogen fuel engine, but there is a risk of hydrogen damage in the welded structure of hydrogen-related components. The tensile, fatigue and nanoindentation test pieces of welded TC4ELI with 0.2% hydrogen were obtained by electron beam welding and high temperature gas charging of hydrogen. Combined with X-ray diffraction, secondary ion mass spectrometry and other microscopic characterization methods, mechanical tests such as nanoindentation and low-cycle fatigue tests were carried out to deeply investigate the influence of hydrogen on the microstructure and mechanical properties of TC4ELI welded joints. The results show that hydrogen charging can promote the transformation of α phase into β phase and precipitate δ hydride in each zone of TC4ELI welded joints. More hydride precipitated in the weld metal, and the corresponding elastic modulus and hardness decreased the most, resulting in uniform microstructure and properties of welded joints. The elastic modulus and fracture strain of TC4ELI welded joints decreased significantly after hydrogen charging, and the fracture mode changed from transgranular dimple fracture to intergranular brittle fracture due to the influence of hydride. The low-cycle fatigue life of hydrogen-charged TC4ELI is significantly reduced due to stress-induced hydride cracking at low stress level; however, at high stress level, due to hydrogen-induced local plasticity, it exhibits better fatigue resistance.

Key words: TC4ELI titanium alloy, electron beam welding, hydrogen damage, microstructure, mechanical properties, nanoindentation

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