Aqueous Corrosion Behavior of Cast CoCrFeMnNi Alloy

CoCrFeMnNi high-entropy alloy demonstrates good mechanical properties and can be further strengthened by thermomechanical processes. A sample alloy prepared by vacuum casting in a graphite mold was further investigated for its corrosion resistance. One-millimeter thin strips of cast alloy were used to investigate its corrosion behavior at room temperature. Linear potentiodynamic tests of the alloy in sodium chloride solution confirmed uniform corrosion property comparable to stainless steel AISI 304. However, a positive cyclic hysteresis loop indicated susceptibility to pitting corrosion. In sodium hydroxide solution, metastable pit formation was observed, while sulfuric acid solution passivated the alloy. In both cases, the alloy did not show any spontaneous pitting tendency.