Abstract
A series of anodic polarization tests on iron-nickel alloys with varying nickel content were carried out in sulphuric acid solution and the results obtained are summarized as follows: (1) The polarization for anodic dissolution of active alloys is the greater, the higher the nickel content, and an increase in nickel favoured the onset of anodic passivity of the alloy anodes. (2) Though, when a passive condition is reached the anodic dissolution of iron and iron-rich alloys of less than about 60%Ni ceases almost entirely, nickel and nickel-rich alloys of more than about 60%Ni does not cease entirely, the dissolution of the latter due to the anodic oxidation being greater, the higher the nickel content and the higher the anode potentail. (3) Iron-nickel alloys passivated by anodic polarization are only temporarily passive. (4) The α-phase alloys containing less than 30%Ni were found to be about 0.15 volt less noble than the γ-phase alloys containing more than 30%Ni in sulphuric acid solution. (5) The formation of the ordered lattice Ni3Fe in alloys reduced the anodic dissolution of the alloys.
