LAUSR

Abstract Fine-grained processing of Inconel 617 sheet was proposed, and microstructural evolution during processing was analyzed. The optimum recovery temperature at 750 °C and the best recrystallization annealing temperature at 1000 °C were determined by experiments. The optimal fine-grained process comprised heat treatment (750 °C × 1 h), first cold rolling (60% reduction rate), high-temperature recovery (750 °C × 1 h), second cold rolling (10% reduction rate), and recrystallization annealing (1000 °C × 3 h). After recrystallization annealing (1000 °C × 3 h), the fine-grained sheet consisted of equiaxed grains with a size of 4–6 μm. A high proportion of high-angle grain boundaries was observed, and most of the grain orientation spread values were less than 1. The grain recrystallized completely. Twin refinement mechanism played a dominant role in sheet grain refinement. The hardness and tensile mechanical properties of the fine-grained sheet were notably stronger than those of the original sheet.