Corrosion Behavior of Several Alloys in Supercritical Water Oxidation Environment at 450 C/23 MPa

The corrosion behavior of four typical Ni-based corrosion-resistant alloys in supercritical aqueous solution containing Na3PO4, Na2SO4, and NaCl at 450 degrees C/23 MPa was studied by XRD, SEM, etc. The results show that after corrosion for 50 h, the surface of the alloys is covered by short rod-shaped and needle-shaped products mainly consisting of NiCr2O4, Cr2O3, NiO, Ni-3(PO4)(2), CrPO4, and Na3PO4. With prolonging the time, the thickness of the corrosion layers is increased and the corrosion resistance is ranked as X-1#>X-2#>625>C-276.