CORROSION-RESISTANCE OF METALS IN HOT HYDROXIDE SOLUTIONS

The effect of the nature, concentration, and temperature of a hydroxide on the corrosion resistance of Russian steels and alloys was studied in hot NaOH, KOH, and LiOH solutions. Special attention was paid to the susceptibility of the metal to corrosion cracking. The corrosivity of hydroxides with respect to the stainless steels and nickel alloys was found to increase in the series LiOH < KOH < NaOH. Isocorrodes for a level of 0.1 mm/year were constructed for all the materials in the unmixed and chlorate-containing solutions of sodium and potassium hydroxides. Temperature and concentration ranges wherein stainless steels and nickel alloys reveal a noticeable tendency to cracking were found for the hydroxide solutions.