The influence of gas high-temperature hot corrosion(HTHC) pre-exposure on low-cycle fatigue(LCF)behavior was characterized for the directionally solidified(DS) Ni-based superalloy DZ125. Fatigue tests were carried out...The influence of gas high-temperature hot corrosion(HTHC) pre-exposure on low-cycle fatigue(LCF)behavior was characterized for the directionally solidified(DS) Ni-based superalloy DZ125. Fatigue tests were carried out at 850 ℃ in the pre-exposed and unexposed specimens for 2, 15 and 25 h. Experimental results show that the porous corrosion scale and γ′-depleted layer formed in gas hot corrosion condition alter the crack initiation mechanisms of the superalloy. Fatigue cracks of the pre-exposed specimens originate from multiple surface locations where spalling of the corrosion products occur,while nucleation of unexposed specimen begins in the defects close to the surface. There is a significant reduction in LCF behavior for pre-exposed specimens in comparison with unexposed specimens.展开更多
基金financially supported by the National Natural Science Foundation of China(No.51571010)the National Basic Research Program of China(No.2015CB057400).
文摘The influence of gas high-temperature hot corrosion(HTHC) pre-exposure on low-cycle fatigue(LCF)behavior was characterized for the directionally solidified(DS) Ni-based superalloy DZ125. Fatigue tests were carried out at 850 ℃ in the pre-exposed and unexposed specimens for 2, 15 and 25 h. Experimental results show that the porous corrosion scale and γ′-depleted layer formed in gas hot corrosion condition alter the crack initiation mechanisms of the superalloy. Fatigue cracks of the pre-exposed specimens originate from multiple surface locations where spalling of the corrosion products occur,while nucleation of unexposed specimen begins in the defects close to the surface. There is a significant reduction in LCF behavior for pre-exposed specimens in comparison with unexposed specimens.