Breakaway corrosion of stainless steels remains a challenge for many industrial applications operating in harsh conditions. The lifetimes of metallic components are often determined by the corrosion propagation after breakaway. Nevertheless, studies on the protective properties of the Fe-rich oxides formed after breakaway are scarce. This study investigates the influence of Ni on the protection after breakaway on a broad range of Fe18CrxNi model alloys, by systematically inducing breakaway of the initially formed protective, Cr-rich oxides. The results clearly demonstrate an improved protection after breakaway for higher Ni-contents, explained by the alloys’ ability to avoid internal oxidation involving Fe-rich BCC and spinel.