Having been deposited on 304 stainless steel (SS304) substrates by RF reactive co-sputtering, 1 μm-thick Ti-Cr-N films were annealed at 400 °C and 700 °C. Accordingly, nitride phases of TiN and CrN, and as a result of the lost capability as an oxygen diffusion barrier, oxide phases of Fe2O3, Cr2O3, and TiO2 formed after the annealing process at 700 °C. For short-term immersion (1 h), the corrosion testing illustrated that the film annealed at 400 °C shows greater corrosion resistance than the other films and SS304. For long-term immersion (30 days), all the films demonstrated greater corrosion resistance than SS304, with the as-deposited film delivering the best performance. It was found that protective passivation layer formation, porosity closures, and surface characteristics such as pits, trenches, grooves, cracks, and protuberances govern the corrosion behavior differences. The surface micrographs imply that pitting corrosion and superficial filiform corrosion are among the underlying mechanisms affecting the surfaces. Finally, given the concerns about the capability of SS304 to release toxic elements such as chromium, it was determined that not only can Ti-Cr-N films increase the corrosion resistance of SS304 but also they can reduce the release of chromium by almost 67% in the long-term exposure.