Nickel superalloys are high-performance materials widely used in aerospace industries due to their exceptional strength, toughness, and high-temperature properties. The microstructure of these superalloys is comprised of gamma prime phases, carbides, oxides, and Prior Particle Boundaries (PPBs), among others. PPBs are formed during the heat treatment process and play a crucial role in determining ductility. During material processing operations such as extrusion, forging, and rolling, the PPBs may rupture, and small fragments disperse randomly within the grain structure. This can create sites for crack initiation and propagation, ultimately reducing the material’s ductility and toughness. In this work, we present a hierarchical multiscale material model to study hardening mechanisms in nickel superalloys, specifically to understand the detrimental effects of PPBs. Physics at the mesoscale is modeled using 2D Discrete Dislocation Dynamics (DDD). Input parameters for DDD, such as the elastic modulus, drag factor, and obstacle strength, are obtained using atomistic simulations. Molecular dynamics simulations of edge dislocations with Burgers vector 12 ⟨110⟩ on {111} planes reveal two distinct dislocation velocity regimes for the γ and γ′ phases. Extensive simulations incorporating both phases that provide insights into the effective dislocation mobility and the effective dislocation-obstacle strengthening mechanisms will be presented–the precipitates are modeled as misoriented Ni3Al phases. These simulations are then used to develop a homogenized γ-γ′ system, the properties of which are fed to the DDD model to understand hardening behavior due to the presence of PPBs under various temperatures and loading conditions. These simulations offer valuable insight into the mechanisms controlling the mechanical behavior of nickel superalloys in the presence of PPBs and can be applied to design components capable of operating under extreme conditions.