The effect of solid solution treatment at 900 ~ 1 190 °C on the corrosion performance of as-cast 2101 duplex steel (/%：0.02C，0.69Si

5.00Mn，0.001 5S，0. 022P，21.42Cr

1.66Ni，0. 31Mo，0. 48Cu，0. 25N) has been investigated by electrochemical corrosion experiments. EIS impedance spectra

equivalent circuit polarization resistance values

and Tafel curves show that at the saine solid solution temperature

the longer the solid solution time

the better the corrosion resistance of steel. From the electron micrographs of structure morphology and the determination of the [-phase area ratio and grain size in the steel

it is obtained that the [-phase area ratio and the number of y grains per unit area increase early and then decrease with increasing solid solution temperature for 30 min and 2 h

and the structure is the densest at 970 °C

and the structure is denser after 2 h of solid solution than that after 30 min of solid solution. 2101 duplex stainless steel corrosion resistance is better as higher dense of structure and less precipitated nitrides. The optimum solid-solution of the steel is at 970 °C for 2 h.