Corrosion analysis of vehicle materials and feasibility assessment of magnesium alloys under deicing agent exposure

The widespread use of sodium chloride and calcium chloride as deicing agents has raised concerns about the accelerated corrosion of automotive components. This study systematically investigates the corrosion behaviour of commonly used automotive steel sheets—cold-rolled and galvannealed (GA)—under varying temperature conditions and brine environments. Results indicate that while calcium chloride initially induces faster corrosion due to its exothermic dissolution, sodium chloride leads to greater cumulative corrosion over time. Tafel analysis and activation energy calculations (0.23 eV for GA steel and 0.13 eV for magnesium (Mg) alloy) reveal temperature-dependent acceleration mechanisms. Notably, Mg alloy sheets exhibited significantly lower mass loss and slower corrosion rates compared to GA steel, due to their lower activation energy and the self-limiting nature of their protective oxide film. These findings highlight the potential of Mg alloys as a viable lightweight alternative for vehicle chassis and powertrain components in electrified vehicles, where mechanical demands are reduced. The results also provide evidence-based metrics useful for long-term corrosion modelling and material selection in automotive applications.