Effects of Vanadium and Other Elements on the Pitting Resistance of a Ferritic 18% Chromium Stainless Steel

The effects of vanadium and other elements on the pitting resistance of an 18% chromium ferritic stainless steel (SS) with less than 168 ppm carbon and nitrogen are reported. Vanadium was added to the base alloy in the concentration range of 1 to 4%, alone and in combination with titanium, niobium, nickel, copper, silicon, and molybdenum (maximum of 2% each). The alloys were tested for resistance to pitting corrosion by potentiodynamic polarization in NaCl, and immersion in FeC13. An overall assessment of the effects of alloying on pitting resistance in the alloys showed the following results: vanadium—beneficial (to detrimental); titanium and niobium—mostly beneficial; nickel—beneficial to variable; copper—detrimental; silicon—beneficial; and molybdenum— very beneficial.