Induction of large twin related domains and the grain boundary evolution during hot plate rolling and annealing of 316H-type stainless steel

摘要

Special thermomechanical processing (TMP) routes of hot rolling and annealing were designed to induce large twin related domains (TRDs) in nuclear-grade 316H plates, and the evolution of twin-related (Sigma 3(n) , 1 = n = 3) boundaries and random high-angle grain boundaries (RHAGBs) was clarified. Results demonstrated that the large TRDs and poor RHAGB connectivity could be induced through hot rolling at 800 degrees C with low-strain followed by annealing. Optimized GB character distributions (GBCDs) presented favourable resistance to intergranular corrosion. Quasi in-situ heating observations showed that the operation of GB migration, recrystallization and grain growth during annealing were necessary to form large TRDs, and the slight deformation storage energy played important role to induce their initiation.