Abstract
Hot-rolled 3207 duplex stainless steel (DSS) was solution treated at 1250 ℃ for 30 min, and cold rolled at 40–80 % reduction. The superplastic deformation was drawn with a constant speed of 1.5 × 10^-3 s^-1at 950 °C. The effect of cold-rolling reduction on microstructure and properties of 3207 duplex stainless steel was studied. The results show that austenite and ferrite are elongated along a rolling direction with increased reduction With the increase of reduction, the elongation of 3207 DSS at a high-temperature tensile process increased significantly. When the reduction reached 70 %, the elongation could exceed 100 %. When the reduction rate of cold rolling reached 80 %, the elongation reached the maximum value of 408.63 %. When the reduction was less than 60 %, the peak stress was stabilized at about 300 MPa. When the reduction reached 60 %, the peak stress decreased gradually with the increase of the reduction, and the lowest value, 140.34 MPa, was obtained when the reduction reached 80 %.

Key words
3207 duplex stainless steel, cold rolling reduction rate, microstructure, high-temperature plasticity

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