I wrote a paper on " origin of corrosion potentials "in BULLETIN OF ELECTROCHEMISTRY , a journal came from CECRI( CENTRAL ELECTROCHEMICAL RESEARCH INSTITUTE KARAIKUDI -6 INDIA
you can ask for reprints from the librarian CECRI KARAIKUDI
OCP becoming noble is an indication of passivity ; that is all
you have to measure the film using ellipsometry or can calculate using CV