The corrosion of ferrous materials is briefly reviewed. The
theory and practice of the impedance methods currently used in the
investigation of electrochemical corrosion reactions are described
in some detail. Special reference is made to the differentia~
capacitance bridge technique.
Using these methods the corrosion of both iron and mild steel
in lM sodium perchlorate under neutral pH conditions has been
investigated. The effect of ions encountered in natural waters has
also been explored, by addition to the base electrolyte. The work
then examineS. the influence of a simple ortho-phosphate compound
as an inhibitor of the corrosion reactions.
Confirmatory evidence is g1ven to support the view that the
point of zero charge on 1ron and mild steel is not attainable at
neutral pH. The effect of alloying materials in mild steel 1S
The results of investigations with ortho-phosphate in the
base electrolyte, containing added natural water constituents, are
consistent with the repair of a protective film at the electrode.
A thesis submitted to Loughborough University
of Technology in fulfilment of the requirements
for the degree of Master of Philosophy.