| This paper presents a systematical study on the interface misorientation distribution and interface plane distribution evolution during cold-rolling and annealing in UNS S31803 duplex stainless steel by means of scanning electron microscopy(SEM),electron backscatter diffraction(EBSD),Rodrigues-Frank(R-F)space and five-parameter method.And then,the intergranular corrosion susceptibility for all specimens as-processed were evaluated by doubleloop electrochemical potentiokinetic reactivation(DL-EPR).The results show that,first,single supersaturated ferrite phase was obtained after solution heat treatment at 1290? for 30 min.After subsequent cold rolling and annealing at 1050?,homogeneous and equiaxed austenite and ferrite duplex microstructure was produced.Low angle grain boundaries(LABs)and major twin boundaries + LABs were found in ferrite and austenite,respectively.Phase boundaries were mostly satisfy so-called K-S and N-W orientation relationship within the deviation degree of 3.5°.Second,{111} planes were populated in austenite whereas grain boundary plane distribution consisting of {0 0 1},{1 1 5} and {1 1 7} changed to {1 1 1} planes with lower boundary energy in ferrite as annealing proceeds.Phase boundary planes also have a tendency to concentrate on {1 1 1}.However,the phase boundary planes satisfying the K-S?N-W and Bain orientation relationship deviate away from the close-packed planes to a certain extent.Finally,the internal boundary character distribution of cold-rolled and annealed DSS with initially solution treatment at 1050? for 30 min was featured by lower LABs and ?3 twin boundaries and phase boundaries of K-S orientation relationship with well ordered structure and therefore exhibited higher susceptibility of intergranular corrosion and low intergranular corrosion resistance compared to the specimens which are initially solution-heat-treated at 1290? when both specimens were subjected to the same cold-rolling and annealing. |
PDF Full Text Request