| 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