Corrosion Behavior of Nickel Based Alloy 825 in High Temperature and High Pressure H₂S/CO₂ Environments

To resolve the materials corrosion problems during exploiting high sulfur oil and gas field,the corrosion behavior of nickel based alloy 825 in high temperature and high pressure environments were studied.The scanning electron microscopy (SEM),energy disperse spectroscopy (EDS) and electrochemical methods were applied to characterize the microstructure and corrosion performance of the samples.The corrosion mechanism was also proposed and discussed.The results indicated that slight corrosion was observed on the alloy surface.Its maximum corrosion rate was 0.068 mm/a.Cracks were not found on the SCC sample surface.However,some pits appeared at grain boundaries of the alloy,indicating that the crystal plane was easily attacked.