Influence of Cr⁶⁺ on Corrosion Behavior of Type 321 Stainless Steel in Uranyl Nitrate Solution

Corrosion behaviors of 321 stainless steel had been investigated in 1-4 mol/L HNO3+50 g/L UO2(NO3)2 solution and 1-4 mol/L HNO3+50 g/L UO2(NO3)2+4 g/L Cr6+ solution.A comparison of the corrosion rates indicated that Cr6+ promoted the corrosion of 321 stainless steel in uranyl nitrate solution.The analysis by SEM and XPS indicated that Cr6+ made Cr2O3 in the surface film of 321 stainless steel dissolved,resulting in the corrosion of grain boundaries and grains.