Abstract The present article addresses the stress corrosion cracking (SCC) and subsequent corrosion fatigue cracking (CFC) behavior of a heat-treated duplex stainless steel (DSS) in paper-machine white waters containing chloride and thiosulfate ions. According to the potentiodynamic and slow strain rate tests (SSRT) carried out in this study, it is believed that crack initiation corresponds to an SCC film rupture process during paper-machine shutdowns where ionic concentrations of species increase due to white water evaporation. Crack initiation occurs by pitting within ferrite grains or near grain boundaries where metallurgical changes produced during heat treatments play an important role. Once cracks have initiated, they will propagate by fatigue during alternate cycling loads produced in normal operation of the paper machine.