NaCl induced corrosion of Zn-0.2Al, Zn-5Al and Zn-55Al coated steel was investigated at low and ambient CO2 levels. Weight loss measurements revealed an enhancement of the corrosion of Zn-0.2Al and particularly Zn-5Al in low CO2. This was connected to an increase of surface pH in a low CO2 atmosphere promoting the formation of ZnO and layered double hydroxide for Zn-5Al. For Zn-55Al, CO2 depletion did not affect the surface pH due to the acidification effect of Al3+. Preferential dissolution of zinc rich phase was observed on cross-sections, particularly in depleted CO2 experiments. Different sequences of corrosion product formation were proposed for the different Zn-Al coatings. (c) The Author(s) 2018. Published by ECS. This is an open access article distributed under the terms of the Creative Commons Attribution 4.0 License (CC BY, http://creativecommons.org/licenses/by/4.0/), which permits unrestricted reuse of the work in any medium, provided the original work is properly cited.