INFLUENCE OF MANGANESE ON THE PROPERTIES OF A VANADIUM-BEARING FERRITIC STAINLESS-STEEL

For the purpose of further increasing toughness, the influence of mang anese contents up to 4% was investigated in a 4% vanadium-bearing expe rimental ferritic stainless steel. The tensile and formability propert ies were also studied. The corrosion properties were measured using el ectrochemical techniques in 1 N H2SO4 and 3.5% NaCl solutions. No mark ed effect was found on the tensile and formability properties. In cont rast, manganese has a strong detrimental effect on the general and loc alized corrosion properties of this 4% vanadium alloy. The passivation characteristics in normal sulphuric acid are much poorer. However, sp ontaneous passivation occurs in this environment where the manganese c ontent is 0.1%. Similarly, the propensity to pitting corrosion is grea tly improved at low manganese levels, with pitting potentials superior to both type 304 and 316L stainless steels.