The microstructure, martensitic transformation and superelasticity were examined in Fe–30Ni–15Co–10Al–2.5Ti–0.05B polycrystalline alloy sheets. Thermoelastic transformation was obtained in an aged specimen at 550°C with the γ (FCC) + γ′ (L12) structure. Moreover, it was found that a {012}〈100〉 recrystallization texture was formed and that the high fraction of low energy boundaries was increased in a 98.5% cold-rolled specimen. Suppression of brittle precipitation during aging was directly observed at those boundaries, resulting in improvement of ductility, and superelastic strain of over 4% was obtained in the polycrystalline alloy in a tensile test at room temperature.