Repassivation potentials,
ER, CREV, for metal/metal-crevices of 54 kinds of stainless steels were measured in 3% NaCl solution at 80°C. Obtained E
R, CREV values were analysed in relations to chemical compositions of the 52 steels into multiple linear regressions in the form of Y=b
0+∑b
jX
j for every one of steel groups, which are α (ferritic, 15 steels), α+γ (duplex, 11 steels), γ (austenitic, 18 steels with Cu<0.4%) and γ
Cu (austenitic, 8 steels with 0.9-3.5% Cu). Y is the predicted value for E
R, CREV and X
j denotes the content of alloying element j in wt% except j=Ni where X
j=log
Ni. Alloyed Cu more than 2% to austenitic steels changes the value of b
logNi from -97mV/decade for γ to +45mV/decade for γ
Cu-group steels. Well known beneficial effects of Mo were confirmed for all groups of steels except the γ
Cu-group steels containing 2-3% Cu, of which E
R, CREV values are kept constant independently on Mo contents. Addition of N up to 0.2% were found to be beneficial for the duplex steels, but not significant for the austenitic steels in spite of beneficial effects of N reported on pitting potentials.
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