Using a combination of state-of-the-art multi-scale computational models and advanced experimental analysis using small angle neutron scattering (SANS), atom probe tomography (APT) and transmission electron microscopy (TEM), kinetics of the phase separation phenomenon will be analysed for commercially available duplex stainless steels. The aim is to use this information in designing as well as in lifetime assessments of these commercial alloys. This will be accomplished by modeling of the structure factor of the evolving nanostructure from SANS, and comparing it with phase-field modeling results solving the Cahn-Hilliard equation. Probing this structural decomposition from the early stages will enable the development of a holistic methodology for the design of novel duplex stainless steels that are less sensitive to low-temperature embrittlement.