Hydrogen embrittlement is a serious problem in the oil/gas industry. In this work, various iron sulfide (Fe-S) films, including iron monosulfide (FeS), pyrite (FeS2), and pyrrhotite (Fe7S8), were synthesized in X80 steel by chemical vapor deposition at 200 degrees C, 300 degrees C, 400 degrees C, and 500 degrees C. The corrosion resistance and hydrogen permeation properties of the Fe-S films were investigated through electrochemical methods. Results indicated that Fe-S films significantly improved the hydrogen barrier properties of the X80 steel, which was closely related to the crystal structure type and defects of Fe-S films. Defects like microcracks and pinholes during deposition can increase the porosity of the film, resulting in the film properties decreased. Moreover, FeS film (at 300 degrees C), which had the smallest apparent hydrogen diffusivity (D (similar to) 2.64 x 10(-7) cm(2)/s) and apparent subsurface concentration (C-app (similar to)1.12 mu mol/cm(3)), had the best hydrogen barrier properties. The corrosion resistance of FeS film (300 degrees C) was excellent. (C) 2018 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.