Abstract The polarisation behaviour of both the shape-memory alloy Fe-34Mn-17Al-5Ni and pure Fe were analysed in NaCl-free and NaCl-contaminated Ca(OH)2,sat solutions. Simultaneously to the polarisation scan, corrosion progression at the interfaces was studied in-situ and correlated to the applied overpotentials. In NaCl-free Ca(OH)2,sat, FeMnAlNi and Fe behave similarly, and are characterised by pronounced passivity at low overpotentials and intensive O2 evolution at high overpotentials. In NaCl-contaminated Ca(OH)2,sat, FeMnAlNi exhibits more severe pitting corrosion sensitivity than Fe. The pitting behaviour is rationalised based on the different semiconducting properties of the passive oxides, which were analysed by the Mott-Schottky technique.