Effects of γ/γ′eutectic on corrosion resistance of GH4720Li superalloy
MENG Ling-sheng1,2, DUAN Fang-zhen3, AN Teng1,2, SHI Yu-ting1,2, QU Jing-long1,2, DU Jin-hui1,2
1. Beijing CISRI-GAONA Materials and Technology Co. , Ltd. , Beijing 100081, China; 2. Beijing Key Laboratory of Advanced High Temperature Materials, Central Iron and Steel Research Institute, Beijing 100081, China; 3. College of New Energy and Materials, China University of Petroleum, Beijing 102249, China
Abstract：The influence of γ/γ′eutectic on corrosion resistance of GH4720Li superalloy was studied by electrochemical test. The microstructure and interphase potential of the eutectic phase structure before and after corrosion were observed by optical microscope and atomic force microscope. The results showed that the γ/γ′eutectic phase in GH4720Li supperalloy is formed by the partial aggregation of Al and Ti elements. The results of electrochemical test, in situ corrosion observation and atomic force microscope test all showed that the γ/γ′eutectic phase resulted in the decrease of corrosion resistance of the superalloy.The low corrosion resistance element mass fraction and continuous distribution of the phase in the γ/γ′eutectic phase of GH4720Li superalloy are the fundamental reasons of the decrease of corrosion resistance.
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2020, Vol. 30 
