Posted by J URUCHURTU CHAVARIN on July 29, 1996 at 12:44:41:
In Reply to: Electrochemical Response of Nickel in Artificial Seawater posted by A.AL-HASHEM on July 28, 1996 at 13:49:40:
: I ment to send the comments regarding the pitting of
: Monel 400 to you since this alloy is nickel-based.
: Anyway, if you are not watching the 96 Olympics in
: Atlanta, would you reply to my comments if applicable.
: As I mentioned in my note,did you encounter any pitting
: under free corrosion conditions for the alloy(s) you
: have studied? We observed pitting of monel 400 only
: when the samples were anodically polarized in natural
: or different concentrations of NaCl solutions.
: Thank you.
:
ANSWER:WE DID NOT PERFORM LONG TERM TESTS IN
ARTIFICIAL SEAWATER. ANYWAY FROM MY PRACTICAL
EXPERIENCE AND FROM THE RESULTS OBTAINED AND
PRESENTED HERE, NICKEL PITS ONLY UNDER ANODIC
POLARIZATION ALTHOUGH THERE IS SOME EVIDENCE IN
THE LITERATURE THAT UTILIZING ELECTROCHEMICAL
NOISE IT IS POSSIBLE TO OBTAIN SOME TRANSIENTS
ASSOCIATED TO METASTABLE PITTING UNDER FREE
CORROSION CONDITIONS.