Corrosion behavior of nickel-based 718 alloy determined by in situ electrochemical methods at different partial pressures of H2S in 25 wt% NaCl solution at 150℃  

作　　者：Yu-Bi Zhang Xiao-Liang Yang An Tang 

机构地区：[1]School of Mechanical Engineering,Henan University of Engineering,Zhengzhou 451191,China [2]Chongqing Materials Research Institute Co.,Ltd,Chonging 400707,China

出　　处：《Rare Metals》2019年第9期855-863,共9页稀有金属（英文版）

基　　金：financially supported by the Science and Technology Open Cooperation Project of Henan Province (No. 172106000062);the Science and Technology Development Project of Henan Province (No. 182102310837);the HighSchool Science and Technology Innovation Team Support Plan of Henan Province (No. 18IRTSTHN005)

摘　　要：The corrosion behavior of nickel-based 718 alloy at seven partial pressures of H2 S(PH2 S)was investigated using electrochemical impedance spectroscopy(EIS)and polarization methods in 25 wt% NaCl solution at150℃ for 168 h.The tested results show that anodic reactions are controlled alternately by the diffusion mostly,then both charge transfer and diffusion and finally charge transfer mainly with the increment of PH2 S.The corrosive products are composed of sulfides and oxides of Ni,Cr and Fe with double layers for PH2 S of 5.1 and 13.0 MPa and three layers for PH2 S of 10.4 MPa according to microstructures and compositions of corrosion products characterized by the scanning electron microscope(SEM)and electron probe microanalysis(EPMA)methods.The inner oxides layer plays a critical role in anti-corrosion in a wet H2 S environment at high temperature and pressure.The corrosion behavior of nickel-based 718 alloy at seven partial pressures of H2 S(PH2 S)was investigated using electrochemical impedance spectroscopy（EIS）and polarization methods in 25 wt% NaCl solution at150℃ for 168 h.The tested results show that anodic reactions are controlled alternately by the diffusion mostly,then both charge transfer and diffusion and finally charge transfer mainly with the increment of PH2 S.The corrosive products are composed of sulfides and oxides of Ni,Cr and Fe with double layers for PH2 S of 5.1 and 13.0 MPa and three layers for PH2 S of 10.4 MPa according to microstructures and compositions of corrosion products characterized by the scanning electron microscope（SEM）and electron probe microanalysis（EPMA）methods.The inner oxides layer plays a critical role in anti-corrosion in a wet H2 S environment at high temperature and pressure.

关 键 词：Nickel-based 718 alloy Corrosion ELECTROCHEMISTRY Polarization Passive film 

分 类 号：TG178[金属学及工艺—金属表面处理]