Role of copper and aluminum on the corrosion behavior of austenitic Fe–Mn–C TWIP steels in aqueous solutions and the related hydrogen absorption

• Corrosion behavior and related H absorption of TWIP steels have been investigated.
• We used isotropic tracing of H with deuterium to characterize H absorption.
• Metallic Cu in oxide layer favors H recombination and decreases H absorption.
• Al in oxide layer decreases the average corrosion rate and the related H absorption.
• In Al-enriched alloy, the presence of P promotes corrosion and related H absorption.

Corrosion tests, isotopic tracing and surface analyses were used to study the corrosion behavior and the related hydrogen absorption of a Fe–18Mn–0.6C alloy in aqueous solutions. The influence of alloying elements was investigated. Copper addition leads to the formation of an oxide layer enriched in metallic copper, which favors H recombination and decreases H absorption in the alloy. Aluminum addition decreases the average corrosion rate by the formation of an oxide layer enriched in aluminum, thus decreasing the hydrogen absorption during the corrosion process. In this Al-enriched alloy, the presence of phosphorus increases the corrosion kinetics and promotes hydrogen absorption.