A method for calculating the anodic polarization curves of binary alloys from those of their components is presented. Heterogeneous alloys can be treated as simple galvanic couples, but homogeneous alloys are subject to a modification of Tammann's concept of surface enrichment. Potentiostatic anodic polarization curves are used to compare the calculated and experimental curves. Data are presented for the tin‐zinc, cadmium‐zinc, iron‐chromium, titanium‐chromium, and iron‐titanium systems.