Based on Cahn-Hilliard diffusion equation

the time-space function was used to define the field variables to describe the composition evolution with time.The phase-field model was used to predict the Spinodal decomposition of Fe-35 Cr

Fe-40 Cr and Fe-45 Cr alloys to analyze the volume fraction

average particle size and particle size distribution of precipitates.The results show that the morphology of the α′ phase in the Fe-Cr alloy presents initially worm-like.With the increase of aging time

the worm-like α′ phase is gradually grown and transformed to ellipsoid or rod-like structure.As the increase of Cr concentration

the average radius and equilibrium volume fraction of the α′ phase are increased.And the nucleation

growth and coarsening rate are accelarated.The simulated results are helpful to understand the phase decomposition of Fe-Cr alloy and the design of high temperature duplex stainless steel.