A comprehensive understanding of the formation of the sigma phase resulting from the
eutectoid reaction (δ→σ+γ2) is required. The kinetics necessary for the eutectoid reaction
are closely related to the amount of plastic deformation in DSS. This work investigates the
microstructural evolution of the σ phase in a 22Cr–5Ni SAF 2205 DSS after subsequent
plastic deformation and isothermal aging. The precipitation of the σ phase resulted from
the higher driving force for precipitating intermetallic compounds and the higher diffusion
rate of their elements by cold-rolling, as well as the sufficient supply of molybdenum. The
maximum amount of σ phase precipitation remarkably increased with an increasing cold
deformation, as compared with the non-cold-rolled materials.