CORROSION OF NICKEL, SOME OF ITS ALLOYS, AND STAINLESS STEELS IN GAPS IN SEA WATER.

The marked accumulation in the gap of corrosion products, obviously NiCl//2, reduces the pH as the result of hydrolysis. The corrosion of nickel at low pH and normal oxygen concentrations (about 8 mg/liter) is determined by oxygen depolarization. This is obvious from the fact that a decrease in the oxygen to about 0. 3 mg/liter causes almost complete suppression of corrosion. At a pH below 4, there is no protection for the nickel, which inhibits oxygen reduction.