Conclusion

As observed in this article, the oxidizing power [in the sense of oxide(s) formation] of the atmosphere is the key factor in corrosion. In chlorinating industrial environments clearly defined as oxidizing (Cl ₂ /O ₂ ) or reducing (HCl/H ₂ ), the choice of materials can be based on a good knowledge of the mechanisms involved. The difficulty lies in chlorine-rich atmospheres where oxygen is a residual. It will then be necessary to play on the composition of the alloys, by increasing the contents of highly reducing additive elements (Al, Si) which can generate a protective oxide film, and/or to modify the gas phase by intentionally increasing the oxygen content, in order to control it in a range where these protective films are stable.