Effects of Deformation Mode and Strain Level on Grain Boundary Character Distribution of 304 Austenitic Stainless Steel

In this study, the effects of deformation mode (rolling and tension) and strain level on grain boundary character distribution were systematically investigated in 304 austenitic stainless steel. The experimental results showed that the 〈110〉 component parallel to the normal direction orientation and the P(B_ND) {110}〈111〉 texture were predominant in the rolled specimens and the tensioned ones, respectively. For each mode of deformation, the fraction of low-Σ coincidence site lattice (CSL) boundaries, especially Σ3ⁿ (n = 1, 2, 3) boundaries decreased with the increasing strain level after annealing. At a lower strain level, the type of texture played a leading role in grain boundary reconstruction during annealing, and the 〈110〉 component parallel to the normal direction orientation facilitated the formation of low-Σ CSL boundaries during annealing compared with the P(B_ND) texture. However, for a higher strain level, the stored energy became dominant in grain boundary reconstruction during annealing, and a large stored energy was detrimental to the formation of low-Σ CSL boundaries, which resulted in a higher fraction of low-Σ CSL boundaries in the tensioned specimen than that in the rolled one after annealing.