Influence of delta phase precipitation on static recrystallization of cold-rolled Inconel 718 alloy in solid solution treatment

Due to the improvement in fatigue strength of cold-rolled blades, the static recrystallization behavior of cold-rolled Inconel 718 alloy in the solid solution treatment was investigated with the methods of optical microscopy and electron backscattered diffraction. The effect of δ phase precipitation on the static recrystallization process was also analyzed. The results show that δ phase preferentially precipitates comparing to static recrystallization. Affecting by the δ phase preferential precipitation process, sub-grain migration is the main nucleation mechanism in the static recrystallization of cold-rolled Inconel 718 alloy at 980 °C. Meanwhile, strain-induced boundary migration also exists as an aided nucleation mechanism when the rolling reduction is less than 30%.