High-Temperature Corrosion in Gas Turbine and Steam Boilers by Fuel Impurities—Part VI: A Statistical Study of the Effects of Sodium, Temperature and Additive on Corrosion Rate and Slag Friability

Corrosion rate and slag friability data on several systems containing Na₂SO₄, V₂O₅, PbO, MgSO₄, and SiO₂ have been examined with a stepwise regression correlation procedure. Correlations were developed relating Na/V, additive/V and temperature as independent variables to corrosion rate and slag friability as dependent variables. The superiority of magnesium over silicon as a corrosion inhibitor was demonstrated while the opposite was shown for slag friability. A critical Na/V ratio was found for certain additive levels and temperature. Below this level, the corrosion rate can be reduced to a minimum. Threshold temperatures were also established. Above these temperatures, the corrosion rate cannot be reduced to zero regardless of the Na/V ratio.