Pitting corrosion of nickel alloys and its inhibition by some dihydrazide derivatives

Pitting corrosion of nickel and its alloys (Inconel 600 and Incoloy 800) in 0.1 M H 2 SO 4 solution containing of NaCl was studied using cyclic voltammetry and potentiodynamic anodic polarization techniques. The integratedcharge amounts Δq a in presence of Cl - ions was taken as a measure of pitting corrosion. The pitting potential was varied with Cl - ion concentrations according to an S-shaped curves. Addition of dihydrazide derivatives of malonic, succinic and adipic acid caused a shift of pitting potential in the noble direction accounting for increased resistance to pitting attack.