Effect of strain on corrosion resistance of 316L stainless steel as bipolar plates in PEMFC environment

• Planar dislocations in stainless steel improved corrosion resistance in PEMFC environment.
• Large tensile strain deteriorated corrosion resistance of stainless steel in PEMFC environment.
• More fluoride ions decreased corrosion resistance of stainless steel in PEMFC environment.

The effect of the strain of 316L stainless steel on its corrosion resistance in PEMFC environment was investigated. Higher tensile strain facilitated the formation of more dislocations. The 316L stainless steel with 20% strain showed the best corrosion resistance in PEMFC environment containing a few fluoride ions, however, the corrosion resistance of the stainless steel decreased with the increasing of engineering strain in PEMFC environment with a considerable amount of fluoride ions. The morphology and density of the dislocations in strained 316L stainless steel could both affect significantly its corrosion resistance in PEMFC environment. This conclusion was supported by Mott–Schottky measurement and XPS analysis.