Effect of cold rolling reduction rate on high-temperature plasticity of 3207 duplex stainless steel

Hot-rolled 3207 duplex stainless steel (DSS) was solution treated at 1250 degrees C for 30 min, and cold rolled at 40-80 % reduction. The superplastic deformation was drawn with a constant speed of 1.5 x 10-3 s-1 at 950 degrees 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 %.