Corrosion Behavior of Low Temperature Rolled and Annealed CrCoNi Medium Entropy Alloys in 3.5%NaCl Solution

In order to study the corrosion resistance of low-temperature rolled and annealed CrCoNi medium entropy alloy in NaCl solution， the CrCoNi medium entropy alloy deformed by low-temperature (-196 ℃) rolling was annealed at 800 ℃for 30 min.The corrosion resistance of low-temperature rolled and annealed samples in 3.5%(mass fraction) NaCl solution was characterized and analyzed by metallographic microscope， transmission electron microscope， atomic force microscope， photoelectron spectrometer， electrochemical workstation and other testing methods.Results showed that the corrosion resistance of low-temperature rolled samples was poor.After annealing at 800 ℃for 30 min， the corrosion resistance of the samples was significantly improved.Owing to the recrystallization behavior of the rolled state alloy after annealing，grain refinement occurred， and the content of Cr2O3 and Cr(OH)3 in the passivation film on the alloy surface increased， thereby improving the corrosion resistance of the alloy.