The corrosion behavior of porous Ni–Cr–Fe alloy in 2 mol L−1 alkaline solution

Abstract

Abstract Ni–Cr–Fe alloy samples with different porosities were prepared via the Kirkendall effect, with a reactive synthesis of Ni, Cr, and Fe elemental powders. The microstructure, surface morphology and the compositions were analyzed with X-ray diffraction and scanning electron microscopy. The corrosion behavior was explored in a 2 mol L−1 KOH solution using electrochemical methods and an immersion test. The polarization resistance indicated that the free corrosion potential and the lower corrosion current of the porous Ni–Cr–Fe alloy were −0.18528 V and 3.5998 × 10−7 A cm−2. The immersion test showed that after 25 days of immersion, the weight change of porous Ni–Cr–Fe alloy was 0.132 %, which was less than the porous Ni (0.346 %). X-ray photoelectron spectroscopy results revealed the corrosion products of the porous Ni–Cr–Fe alloy and the porous Ni. The corrosion mechanism of the porous Ni–Cr–Fe alloy was discussed.