Texture and Planar Anisotropy in Lean Duplex Stainless Steel Sheet

Abstract

The comparison of texture and planar anisotropy of the r-value between the lean Type 32101 (21.2%Cr-1.5%Ni-5.0%Mn-0.3%Mo-0.02%C-0.22%N) and standard Type 329J4L (25.2%Cr-6.9%Ni-0.7%Mn-3.0%Mo-0.02%C-0.11%N) duplex stainless steel cold-rolled and annealed sheets were examined. Type 32101 had a weaker texture, especially in the α phase, and a lower planar anisotropy of the r-value compared with Type 329J4L. These differences were caused by the cold rolling texture because the α bcc fiber ( < 011 > // RD) texture in Type 32101 decreased during cold rolling. It was revealed that during cold rolling, inhomogeneous deformation easily occurred in Type 32101 because this steel contained a higher volume fraction of the γ phase harder than the α phase.

The Crystallographic Textures and Anisotropy in 2507 Super Duplex Stainless Steel

“…The volume fractions of the {111} and {001} orientations in the γ phase are much smaller than for the α phase, and there are no obvious differences in the different directions. Therefore, it can be further judged that the grain orientation of the α phase plays a major role in determining the mechanical properties and the r ‐value of the sheet; this outcome is consistent with results from previous studies in DSSs …”

Effect of Nitrogen on Planar Anisotropy of the <i>r</i>-value and Texture in Lean Duplex Stainless Steel Sheets

“…These results are similar to those reported previously. 8,9) After high-temperature annealing before cold rolling, the intensity of the α bcc -fiber in the α phase became considerably weaker; this result is similar to that obtained for Type 329J4L, and it is guessed that the α phase morphology before cold rolling affects the local inhomogeneous deformation during cold rolling, the nucleation sites or the growth of subgrains during annealing. 7) In contrast, for 0.05%-nitrogen-added steel, the intensity of the α bcc -fiber in the α phase was relatively weak, and the {110} < 001 > , i.e., Goss orientation, developed with high-temperature annealing before cold rolling.…”

“…Such reverse V-type was also observed in earlier studies of DSS sheets. [3][4][5][6][7][8][9] However, the planar anisotropy changed when the added nitrogen amount decreased to 0.05% at the same annealing condition. With an increase in the annealing temperature before cold rolling, the anisotropies of highnitrogen-added steels decreased, and the r-values for the 0° and 90° directions increased, whereas and those for the 45° direction decreased.…”

“…With regard to the planar anisotropy of the Lankford value (r-value) of DSS sheets, it has been reported that high-alloy Type 329J4L (25%Cr-7%Ni-3%Mo-0.02%C-0.1%N) shows a noticeable planar anisotropy of so-called reverse V-type with the maximum value in the 45° direction, and that its texture is quite different from that of a single-phase material. [3][4][5][6][7][8][9] In addition, lean Type 32101 (21%Cr-1.5%Ni-5%Mn-0.02%C-0.2%N) also shows reverse V-type planar anisotropy, but its anisot-ropy is lower than that of Type 329J4L. 9) In austenitic single-phase materials, reverse V-type anisotropy has been reported, 10,11) but the degree is smaller than DSS sheets.…”

“…[3][4][5][6][7][8][9] In addition, lean Type 32101 (21%Cr-1.5%Ni-5%Mn-0.02%C-0.2%N) also shows reverse V-type planar anisotropy, but its anisot-ropy is lower than that of Type 329J4L. 9) In austenitic single-phase materials, reverse V-type anisotropy has been reported, 10,11) but the degree is smaller than DSS sheets. In the reports of ferritic stainless steel sheets with single-phase, most are V-type anisotropy, and it is known to be in reverse V-type with high reduction (approximately 90%) in cold rolling.…”