The Effect of Oxidative Oxyanions on the Corrosion Behaviour of Commercial Stainless Steels in Hot Concentrated Caustic Soda Solutions

The effect of Na2CrO4, NaBiO3 and NaClO3 on the corrosion of stainless steels has been investigated mainly by means of a potentio dynamic method and measurement of corrosion loss in 48%NaOH solution at 413 K. The presence of oxidative oxyanions in the caustic solution shifted the corrosion potential of steels to the noble direction. The oxidation power of such oxyanions increased with increasing concentration of them in the solution in the following order: ClO3−