Representation of relative positions

The initial consideration in analyzing an existing or proposed metal/environment combination for possible corrosion is determination of the stability of the system. According to Eq 1.18, the criterion is whether the equilibrium half-cell potential for an assumed cathodic reaction, E x, is greater than the equilibrium half-cell potential for the anodic reaction, E M. A convenient representation of relative positions of equilibrium half-cell potentials of several common metals and selected possible corrodent species is given in Fig. 1.7. To the left is the scale of potentials in millivolts relative to the standard hydrogen electrode (SHE). The solid vertical lines identified by the name of the metal give... 

Fig. 5.8 Schematic representation of relative positions of anodic metal, cathodic hydrogen, and cathodic water polarization curves, pH = 1. Curve M, anodic polarization for metal (e.g., Fe-18% Cr) curve H, cathodic polarization for H+ curve W, cathodic polarization for H20 curve SC, sum of H+ and H20 polarization...

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