Microstructure Evolution During Annealing of Inconel 625 and the Effect of Partially Recrystallized Structure on Mechanical Properties

This work produced partially recrystallized microstructures by cold rolling and annealing Inconel 625 sheets to simultaneously achieve excellent strength and ductility. The results showed that the sample achieved excellent ultimate tensile strength (1010 MPa) while retaining good total elongation (68%) when most of its equiaxed grains coexisted with a small number of its non-recrystallized elongated grains. The microstructural heterogeneity is caused by preferential recrystallization at high-strain zones due to non-uniform deformation. And the coexistence of excellent strength and ductility is attributed to the coexistence of non-recrystallized grains at a relatively high internal dislocation density and small-sized strain-free recrystallized grains.