Effect of annealing temperature on the microstructure evolution and corrosion behavior of Carbon-interstitial FeMnCoCrNi high-entropy alloys

The microstructure evolution, corrosion resistance, and passive-film properties of an interstitial FeMnCoCrNi high-entropy alloys annealed at different temperature were investigated. Deformation twins, Strip-shape and ellipsoidal M23C6 carbides are remained within grains and precipitated along the grain boundaries of the HEAs annealed at 500 and 700 °C. The 900 °C annealed i-Cantor alloys are fully recrystallized without deformation twins and precipitated with round M23C6 carbides. The corrosion resistance of the cold-rolled HEAs was deteriorated by annealing at 500 and 700 °C, but improved by annealing at 900 °C, which decreases the dislocation densities and depresses the Cr-depleted regions in i-Cantor alloys.