Abstract: The mechanical properties,corrosion resistance,and the Ferrite-Austenite（α-γ） dual-phase structure of the overlaid duplex stainless steel were analyzed,which was deposited by Flux-cored Arc Welding（ FCAW） with CO₂ gas shielded on the low-carbon steel plate. The results show that the E2209T1-1 flux cored wire,the method of air cooling and the welding heat input of 20. 25 k J/cm have no significant effects on the mechanical properties of the surfaced layer. The surfacing layer is mainly composed of massive Ferrite and acicular Austenite along the Ferrite grain or sub-crystal boundaries. The ferrite content of the surfacing layer can reach up to 42%,which makes the surfacing layer more superior performance and corrosion resistance.