Fatigue behavior of uncoated and MCrAlY-coated DS nickelbased superalloys pre-exposed in hot corrosion condition  

作　　者：Hong-Yu Qi Ji-Shen Yang Xiao-Guang Yang Shao-Lin Li Li-Qiang Ma 

机构地区：[1]School of Energy and Power Engineering,Beihang University,Beijing 100191,China [2]Collaborative Innovation Center for Advanced Aero-Engine,Beijing 100191,China [3]Beijing Key Laboratory of Aero-Engine Structure and Strength,Beijing 100191,China [4]Shenyang Aeroengine Research Institute,Shenyang 110015,China

出　　处：《Rare Metals》2018年第11期936-941,共6页稀有金属（英文版）

基　　金：financially supported by the National Basic Research Program of China(No.2015CB057400);the National Natural Science Foundation of China(No.51571010)

摘　　要：The effects of a MCrAlY coating on low-cycle fatigue(LCF) behavior of directionally solidified(DS)nickle-based superalloy DZ125 were investigated. Before the fatigue testings, the specimens were pre-exposed in high-temperature hot corrosion(HTHC) environment generating by a burner rig at 850 ℃. The results show that the coating in hot corrosion condition has beneficial effects on the fatigue resistance of superalloy. Under corrosion condition, the MCrAlY-coated specimens tested have higher fatigue lives than the uncoated specimens at the same stress level. The coating failure results from fatigue process and numerous fatigue cracks were nucleated at the specimen surface, only one main crack propagates inward and the secondary cracks away from the fracture surface are perpendicular to the loading orientation.The effects of a MCrAlY coating on low-cycle fatigue(LCF) behavior of directionally solidified(DS)nickle-based superalloy DZ125 were investigated. Before the fatigue testings, the specimens were pre-exposed in high-temperature hot corrosion(HTHC) environment generating by a burner rig at 850 ℃. The results show that the coating in hot corrosion condition has beneficial effects on the fatigue resistance of superalloy. Under corrosion condition, the MCrAlY-coated specimens tested have higher fatigue lives than the uncoated specimens at the same stress level. The coating failure results from fatigue process and numerous fatigue cracks were nucleated at the specimen surface, only one main crack propagates inward and the secondary cracks away from the fracture surface are perpendicular to the loading orientation.

关 键 词：MCrAlY coating Low-cycle fatigue Directionally solidified Ni-based superalloy Hot corrosion Prior exposure 

分 类 号：TG174.4[金属学及工艺—金属表面处理]