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The present article deals with effect of Cr addition (10 at.%) on the partitioning behavior and the consequent effect on mechanical properties for tungsten-free γ–γ′ cobalt-based superalloys with base alloy compositions of Co–30Ni–10Al–5Mo–2Ta (2Ta) and Co–30Ni–10Al–5Mo–2Ta–2Ti (2Ta2Ti). Cr addition leads to a change in the morphology of the strengthening cuboidal-shaped γ′ precipitates to a spherical shape. The site preference of Cr atoms in two alloy systems (with and without Ti) has been experimentally investigated using atom probe tomography with the supportive prediction from first principles DFT-based computations. Cr partitions more to the γ matrix relative to γ′. However, Cr also has a strong effect on the Ta and Mo partitioning coefficient across γ/γ′ interfaces. The value of partition coefficient for Mo (K _Mo) becomes <1 with Cr addition to the alloys. Results from ab initio …