SPECIATION OF OXO-CHROMIUM(VI) ANIONS AND THE CORROSION INHIBITION OF AL ALLOYS

摘要

The corrosion inhibitor, hexavalent Cr or Cr(VI), equilibrates among a number of different oxo-Cr(VI) anionic species in aqueous solution. The inhibition mechanism of Cr(VI), particularly at the low pH in pits, depends on which of the several species dominate. Presented theoretical and experimental details of the speciation of hexavalent Cr as a function of pH have important implications for corrosion inhibition in localized environments such as in pits.