| Abstract: | The corrosion resistance of an Fe-40%Cr superferritic alloy containing various major and minor alloying additions, e. g. nickel, molybdenum, aluminium, zirconium, nitrogen, niobium, titanium and ruthenium, as well as various combinations of them, was investigated in dilute sulphuric acid. Although small nickel and molybdenum additions alone cannot cause spontaneous passivation of the Fe-40%Cr alloy to which they are added, a combination of these two alloying elements result in an Fc-40%-Cr superferritic stainless steel which can passivated spontaneously in dilute sulphuric acid. Further additions of minor alloying elements like Ti, Nb, Ru and N have an influence on the time required to achieve spontaneous passivation and the final open-circuit potential eventually reached. Further additions of Al and Zr to the Fe-40%Cr-2%Ni-2%Mo alloy did not have much of an effect on the final open-circuit potential reached, and only affected the time required before this potential was reached in each case. |
