The effect of NaCl concentration on the corrosion behavior of aluminum containing iron

Abstract

Electrochemical measurements and metallurgical observations have been made to clarify the effect of NaCl concentration on the corrosion behavior of the intermetallic compounds such as FeAl 3 in aluminum. The preferential dissolution of iron in the intermetallic compounds and subsequently deposition of ferrous iron occurs in the dilute NaCl solution environment (<1.0 M NaCl). In a concentrated NaCl solution environment (>3.0 M NaCl) the intermetallic compounds provide cathodic sites at which oxygen reduction reaction takes places. Dissolution of the intermetallic compounds is dependent on the variation of the corrosion potentials (open-circuit potentials); the corrosion potentials are equal to the pitting potentials related to the concentrated NaCl solutions.