Electrochemical Corrosion Behavior of Cold-Sprayed Cr2AlC Coating on H13 Steel in 3.5 wt.% NaCl Solution

A cold-sprayed Cr2AlC coating was deposited on an H13 tool steel substrate, and the electrochemical corrosion behavior in 3.5 wt.% NaCl solution was experimentally investigated. Electrochemical tests, including open circuit potential and potentiodynamic polarization measurements, revealed that the Cr2AlC coating significantly improved the corrosion resistance of H13 steel, exhibiting a more positive open circuit potential and a reduced corrosion current density compared with the bare H13 steel substrate. Post-corrosion surface morphology analysis by scanning electron microscopy showed extensive pitting corrosion on the substrate surface, while no obvious corrosion damage was observed on the coating surface. X-ray photoelectron spectroscopy (XPS) analysis further confirmed the formation of a passive film composed of chromium and aluminum oxides on the coating surface, indicating a protective passivation mechanism. The enhanced corrosion performance is attributed to a synergistic mechanism involving both a physical barrier provided by the coating and surface passivation induced by the Cr/Al-based oxide layer. This work highlights the potential of cold-sprayed Cr2AlC coating as an effective corrosion protection solution for steel substrates in chloride-containing environments.