Corrosion behaviour and characteristics of reforming chromized coatings on SS 420 steel in the simulated environment of proton exchange membrane fuel cells

Low-temperature pack chromization is utilized in combination with various activating pretreatment methods, including rolling and electrical discharge machining, to improve the performance of SS 420 stainless steels in the simulated environments of proton exchange membrane fuel cells (PEMFCs). The corrosion resistance and hydrophobicity of chromized steels are enhanced with the pretreatments. The rolled and chromized steel possessing a continuous, uniform, and hydrophobic coating exhibits the best corrosion resistance and stability among all tested specimens. Furthermore, the specimen exhibits the smallest interfacial contact resistance at a compaction pressure of 140 N cm−2, among all tested specimens.

Research highlights
► Reducing chromization temperature for steels via rolling or EDM pretreatment
► The performance of steel bipolar plates in simulated environments of PEMFCs
► Corrosion behaviour and characteristics of reforming chromized coatings
► Promoting corrosion resistance, hydrophobicity, and conductivity of the steel