Evolution of interface character distribution in duplex stainless steel processed by cross-rolling and annealing

Abstract

Duplex stainless steel UNS S31803 samples were cross-rolled with a true strain of ε=2 followed by annealing at 1323K for 2min and 240min, respectively. The distributions of intervariant boundary planes in the precipitated austenite (A) from ferrite (F) and phase boundary planes conforming to Kurdjumov-Sache (K-S) orientation relationship (OR) were characterized by electron backscatter diffraction (EBSD) and the five-parameter analysis (FPA) method, respectively. The intervariant boundary planes with misorientation angle of 60° around <111> and <011> occur frequently and tend to terminate on the {111} plane. At the grain size level of 4μm, the phase boundary appears to be connected with the K-S OR terminating on {110}F‖{111}A at the early stage of annealing. When the grain size reaches approximately 20μm, phase boundary was modified into {541}F‖{533}A due to twinning in austenite during annealing.