Molecular dynamics (MD) simulations of Fe40Cr25Ni35 and Fe50Cr20Ni30 alloys were performed at room temperature, with applied shear stresses ranging from 100 to 500 MPa, to evaluate the dislocation mobility, Poisson ratio, and shear modulus. The average velocity of the dislocation was used to obtain the linear drag coefficient and the dislocation mobility. These parameters were then applied as input parameters in dislocation dynamics (DD) simulations to assess the evolution of dislocation density as a function of time and applied stress, as well as the stress-strain relationship. Our results further demonstrate the benefit of coupling MD-DD simulations as a bottom-up approach to assess material mechanical properties at a large scale under a wide range of temperature, stress and strain conditions.