Effect of Temperature on Corrosion Behavior of Laser-Remelted CrFeCoNi Coating

The CrFeCoNi coating was fabricated by the laser remelting method. The microstructure of the coating was detected. The corrosion behavior of coating at different temperatures was investigated by electrochemical measurements. Potentiodynamic polarization test results indicated that the corrosion current density increased with the increase in corrosion solution temperature in 3.5 wt% NaCl and 0.5 mol/L H2SO4 solutions, suggesting that the CrFeCoNi coating exhibited higher resistance to corrosion attack at lower solution temperature. The breakdown potential of the CrFeCoNi coating exhibited a decreasing trend with increasing solution temperature in 3.5 wt% NaCl solution. This indicated that the passive film formed at low temperatures had higher stability. The electrochemical impedance spectroscopy test indicated that the CrFeCoNi coating possessed higher charge transfer resistance at lower solution temperatures. The corrosion mechanisms of the coating at different temperatures were also revealed.