Chloride Corrosion of Seamless Tube Steel 08Cr2AlMo Used for Heat Exchanger in Petrochemical Industries

ABSTRACT 08Cr2AlMo steel is specifically developed for H₂S‐resistant heat exchanger tubes in response to increasing processing of inferior crude oils, and demonstrates extended service life in practical applications. This study investigated its chloride‐induced corrosion under service conditions. Results showed that 08Cr2AlMo exhibited stable passivation with high corrosion resistance in the absence of Cl − . However, it became pseudo‐passivated as Cl − was introduced, indicating destabilization of the surface passive film. In addition, the corrosion resistance of 08Cr2AlMo progressively decreased with increasing Cl − concentration (up to 7 wt.%). Further analysis revealed that Cl − penetrated and degraded the protective corrosion product film formed on 08Cr2AlMo, thus promoting the dissolution of the film and accelerating the substrate corrosion rate. This study provides foundational chloride corrosion data for 08Cr2AlMo, offering critical insights for its application and performance optimization.