Evolution of texture and development of ∑3ⁿ grain clusters in 316 austenitic stainless steel during thermal mechanical processing

Abstract

A type 316 austenitic stainless steel sheet with various texture components along its thickness was slightly cold-rolled and then sequentially annealed at 1000 °C for 80 and 150 min. The evolution of texture and the development of grain clusters in which the grains are interfaced by ∑3ⁿ (n = 0, 1, 2, 3…) boundaries (∑3ⁿ GC) were studied by electron backscatter diffraction (EBSD). The results show that the texture difference along the thickness was minimized, and large (greater than 400 μ) ∑3ⁿ GCs developed after cold rolling and annealing. In situ EBSD examination revealed that each ∑3ⁿ GC was developed by the oriented-growth (OG) of brass ({110}$\langle 112\rangle$), copper ({112}$\langle 111\rangle$) and C1 ({114}$\langle 041\rangle$) orientations (including their geometric variants). These orientations are intrinsically related to ∑3ⁿ misorientations. The abutting ∑3ⁿ GCs with grains of nearly the same or ∑3ⁿ-related orientations usually merged into a larger ∑3ⁿ GC or resulted in an effective disruption of the connectivity of the random high angle grain boundary network.