Effect of Mo Addition on Corrosion Behavior of High-Entropy Alloys CoCrFeNiMo x in Aqueous Environments

Abstract

The corrosion behavior of CoCrFeNiMo x alloys was investigated in aqueous environments, NaCl and H 2 SO 4 solutions, respectively, to simulate typical neutral and acidic conditions. The cyclic polarization curves in NaCl and the potentiodynamic curves in H 2 SO 4 clearly reveal the beneficial effects of Mo and the detrimental effect of σ-phase on the corrosion resistance. The X-ray photoelectron spectroscopy results of CoCrFeNiMo x alloys in H 2 SO 4 solution indicate that Cr and Mo predominate the corroded surface of the alloys, where Mo primarily exists in the form of MoO 3 .