Elevated Temperature Corrosion Of Type 310 Stainless Steel By Vanadium Compounds

The mechanism of the attack of Type 310 stainless steel by vanadium compounds has been studied. Catastrophic attack by a mixture of 67 wt. percent V₂O₅ + 33 wt. percent of NaVO₃ occurred at temperatures of 1900 to 2000 F if the steel had previously been oxidized and air and water vapor were present. In some instances an unidentified phase formed at the steel-slag interface attacked the steel by grain boundary penetration and adsorption of steel grains. A chemical analysis of the slag showed that the chromium-iron and manganese-iron ratios were the same in the slag as in the steel. The nickel-iron ratio, however, was higher in the slag than in the steel. This would suggest the possibility that nickel is selectively absorbed by the slag prior to general attack. 4.2.3, 4.3.3, 3.5.9, 6.2.5