The Crystallographic Textures and Anisotropy in 2507 Super Duplex Stainless Steel

In this work, the annealing textures in different thickness layers and the Lankford parameter (r-value) in 2507 duplex stainless steel (DSS) are studied via tensile testing, X-ray diffraction (XRD), and electron backscatter diffraction (EBSD). The results show that 2507 DSS has poor formability, especially poor deep drawability and noticeable planar anisotropy after cold-rolling with an average r-value of 0.86, a planar anisotropy or of -0.38, and an earring ratio of 7.43. The orientation distribution functions (ODFs) from the different thickness layers show that the texture mainly exists in the ferrite (alpha) phase, and there is a significant texture gradient in the thickness direction. The texture of the alpha phase has a strong alpha-fiber texture (//RD) and an undeveloped gamma-fiber recrystallization texture (parallel to ND). The texture intensity of the austenite (gamma) phase is weak and is mainly composed of Copper {112}, Brass {110}, Goss {110}, and S {123} . The {001} texture component is highly intense in the alpha phase and is the dominant reason for the low Lankford parameter (r-value), whereas the {112} orientation is the main factor for the high planar anisotropy (Delta r). The results of the grain orientations after tensile deformation in different directions show that the maximum volume fraction ratios for the {001} and {111} orientations are the root cause of the largest r-value in the 45 degrees direction.