Aqueous corrosion behaviors of the low-alloy steels with small amounts of Cr, Cu, Ni
and Ca in synthetic tap water were studied by
electrochemical corrosion tests (potentiodynamic polarization tests, electrochemical
impedance spectroscopy (EIS)) and analytical techniques
(XPS, EPMA). Potentiodynamic polarization test represented that all curves showed
active corrosion behavior and corrosion potential was
shifted to noble direction and corrosion rate tended to decrease as the result of
alloying. Results of EIS measurement showed that the more
the content of element, the larger the polarization resistance. It can be seen that
these results were caused by the formation of a coherent
protective film, which contained alloying elements. Actually,
