Effects of grain size and CeO2 addition on the corrosion behaviour of Cr2O3 based ceramics in high temperature supercritical water environment

In this investigation, Cr2O3 ceramics with different grain sizes were prepared and tested in supercritical water (SCW) environment at 650°C /25 MPa for 200 hours. The results show that the stability of Cr 2O³ in SCW was affected by its grain size. In addition, various amounts of CeO2 were added to Cr2O³ to examine the effect of CeO2 on the corrosion behaviour of the Cr 2O³ based ceramic under SCW condition. These Cr 2O³-based ceramics were exposed to an SCW environment at 650°C/ 25 MPa for up to 600 hours. The results showed that adding a proper amount (≤ 5 wt. %) of CeO2 increased the corrosion resistance of Cr2O³-based ceramics in SCW.