K417G合金的环境致脆磨损机理  

Environment-induced Brittle Wear Mechanism of K417G Alloy

作　　者：王振生 谢威 彭真 贺颖茜 曾阳根 WANG Zhensheng;XIE Wei;PENG Zhen;HE Yingqian;ZENG Yanggen(Hunan Provincial Key Laboratory of Mechanical Equipment Health Maintenance,Hunan University of Science and Technology,Xiangtan 411201,China;China Aviation Development South Industry Co.Ltd.,Zhuzhou 412002,China;Hunan South General Aviation Engine Co.Ltd.,Zhuzhou 412002,China;State Grid Hunan Electric Power Co.Ltd.,Loudi Power Supply Branch,Loudi 417000,China)

机构地区：[1]湖南科技大学机械设备健康维护湖南省重点实验室,湘潭411201 [2]中国航发南方工业有限公司,株洲412002 [3]湖南南方通用航空发动机有限公司,株洲412002 [4]国网湖南省电力有限公司娄底供电分公司,娄底417000

出　　处：《材料研究学报》2021年第7期501-509,共9页Chinese Journal of Materials Research

基　　金：湖南省自然科学基金(2020JJ4312)。

摘　　要：采用可控气氛磨损试验机测试含有Ni3Al相的K417 G合金在不同相对湿度空气、真空、氧气、氮气、二氧化碳、氢气和氩气下的摩擦磨损性能,用SEM观察磨损表面形貌,基于线弹性力学计算表面裂纹应力强度因子KI,依据能量学计算合金元素的环境敏感性,研究合金的环境致脆磨损机理。结果表明:磨损工况下,高相对湿度空气中的水蒸汽是导致K417G合金发生氢致脆性磨损的腐蚀介质,水蒸汽与合金中的γ′-Ni3Al反应生成的原子态H导致环境脆性,环境脆性裂纹源在γ/γ′界面以及碳化物与合金基体界面形核,裂纹既沿着γ/γ′界面以及碳化物与合金基体界面扩展,又进入γ′晶粒;合金表面裂纹的应力强度因子KI小于合金的断裂韧性KIC,接触应力不导致磨损表面裂纹;能量学计算表明,空气下,磨损表面裂纹的产生与Al的含量有关,Al的临界含量为5.53%(原子分数)。The friction and wear properties of K417G alloy in air,vacuum,oxygen,nitrogen,carbon dioxide,hydrogen,and argon environments with different relative humidity were assessed by means of a controlled atmosphere wear tester and SEM.Meanwhile,the stress intensity factor KI of the alloy wear surface crack is calculated based on linear elastic mechanics.The environmental sensitivity of alloying elements is also calculated based on energetics.The results show that under wear conditions,water vapor in the air with high relative humidity is the corrosive medium that causes hydrogen-induced brittle wear of K417G alloy.The water vapor reacts withγ′-Ni3Al in the alloy to form atomic H,which causes environmental embrittlement of the alloy.The environmental brittle crack may nucleate at the interfaces ofγ/γ′and carbide/alloy matrix.The cracks not only extend along the interfaces ofγ/γ′and carbide/alloy matrix,but also enter theγ′grains.The stress intensity factor KI of the crack on the alloy surface is smaller than the fracture toughness KIC of the alloy.Therefore,the contact stress on the worn surface of the alloy does not cause cracks wherein.Energetics calculations show that,in air,the occurrence of surface cracks on the wearing alloy is related to the Al content in the alloy,while the critical content of Al is 5.53%(atomic fraction).

关 键 词：金属材料 K417G合金 镍基合金 NI3AL 摩擦磨损 环境致脆 

分 类 号：TH117[机械工程—机械设计及理论]