抄録
This work is concerned with the electrochemical measurement of the concentration depth-profile of Cr near the surface of Fe-Cr alloys. In Fe-Cr alloys, the steady current density (It, p: mA/cm2) in the transpassive region increases with Cr concentration, suggesting that Cr concentration can be evaluated from the measurement of It, p. When It, p-Q (Coulomb/cm2) curves of Cr-depleted Fe-Cr alloys are measured at +1.400V vs S. C. E. (transpassive region) in 1mol·dm-3 H2SO4 (25°C, air open), It, p increases gradually according to the dissolution in the transpassive region, and finally reaches a constant value depending on Cr concentration of matrix. From this It, p-Q curve, the concentration depth-profile of Cr can be obtained by converting It, p into Cr concentration and Q into depth.
