Corrosion Tests of Electro-polished Steels by Spectrophotometry

Abstract

The amounts of corrosion loss of steels electropolished by chromic oxide-phosphoric acid bath were determined by 1, 10-phenanthroline spectrophotometry. The corrosion tests were made in 2×10^-3N sulfuric acid, 1×10^-3N sodium hydroxide, and 2×10^-3N calcium hydroxide solution in the presence or absence of oxygen at 30°C. The amounts of corrosion in the alkaline solution were decreased to about a tenth of that in the acid solution. The tests were applied to 5×10^-3M calcium sulfate solution at 30°C, as well as to the raw water drawn from the Watarase River, Gumma Pref., the main component of which was calcium sulfate. The steels were not so corroded in these solutions as the content of chromium increased.