This study investigates the effect of cold rolling pre-deformation with different reductions on the microstructure and mechanical properties of a novel polycrystalline nickel-based superalloy with low stacking fault energy and precipitation strengthening. The results indicate that cold rolling pre-deformation introduces microscopic substructures in the alloy

including dislocations

anti-phase boundaries (APBs)

stacking faults (SFs)

and Lomer–Cottrell (L–C) locks. The content of these substructures is positively correlated with the pre-deformation reduction. When the predeformation reaches 15%

a small amount of deformation twins are introduced near the grain boundaries

and the content of deformation twins in the 25% pre-deformation specimen further increases. With increasing pre-deformation reduction

the room-temperature tensile strength and yield strength gradually increase

while the plasticity gradually decreases. Due to the presence of nano-twins and grain refinement in the 25% pre-deformation specimen

its strength is further improved compared to the 15% pre-deformation specimen

while its plasticity remains roughly consistent.