The electrochemical properties of three Ni-free duplex stainless steel alloys, designed in-house, were investigated in chloride (0.2M NaCl) solution at room temperature. The corrosion performance was measured in terms of pitting potential (Epit), passive current density (ip), polarization resistance (Rp) and susceptibility to metastable pitting. The results obtained showed that alloy 2 (Fe–16Cr–5Mn–1Mo–1Si–1Cu–0.22N) exhibited the highest corrosion resistance (highest Epit, lowest ip, highest Rp and lowest metastable pitting susceptibility) among the designed alloys. Alloy 2 was also found to be free of any secondary phase precipitations (sigma phase, Cr nitrides, chi phase) when aged at 600–900 °C for 3–50 h owing to its optimized composition.