The semiconductive properties of the passive films have been related to the corrosion resistance of the materials. In this work, the semiconductive characteristics of the layer formed on corrugated bars of stainless steels have been studied. The information has been obtained from capacitance measurements at high frequency. The tests were carried out in solutions that simulate those contained inside the pores of non-carbonated (pH 12.5) and carbonated concrete (pH 9.3). The study is focused on the characterization of passive films on low-Ni, high-Mn, austenitic AISI 204Cu stainless steel. Austenitic AISI 304 grade is used for comparison. Both materials have been cold worked (CW). The influence of the different microstructure of corrugation and bulk material is also considered in the study. The results about the semiconductive properties have been related with the pitting resistance of the materials, determined through anodic polarization curves, and with results of Universal hardness measurements and metallographic characterization. It has been seen that, in these conditions, the passive films exhibit a bi-layer structure, with an oxide that behaves as n-type semiconductor and other that behaves as a p-type. Results prove that the passive layersformed on the real surface of the corrugated bars exhibit clearly different properties than those formed on the core of the same material in identical conditions. The donor densities (Nd), as well as the acceptor densities (Na), increase as microstructural deformation does. The passive layers formed at pH 12.5 also more stoichiometric than those formed at pH 9.3.