Corrosion behavior of an equiatomic CoCrFeMnNi high-entropy alloy compared with 304 stainless steel in sulfuric acid solution

The corrosion resistance and passive film properties of an equiatomic CoCrFeMnNi high-entropy alloy (HEA) compared with 304L stainless steel in 0.1 M H2SO4 solution were investigated. The in-situ element-resolved corrosion analysis shows that selective dissolution of elements in the HEA is not evident compared to a 304 L stainless steel during passivation. The passive film formed on the HEA is enriched in Fe and Mn but depleted in Cr. The low content of Cr and the extensive formation of metal hydroxide in the passive film are responsible for the lower anti-corrosion performance of the HEA.