Method for refining grain size of GH2907 alloy annular forge piece

The invention belongs to the field of metal forging, and particularly relates to a method for refining the grain size of a GH2907 alloy annular forge piece. According to the technical scheme, the method for refining the grain size of the GH2907 alloy annular forge piece comprises the following steps that (1) steel ingot cogging forging is conducted, specifically, at least two upsetting times and two drawing times are adopted, the GH2907 alloy bar forming forging heating temperature ranges from 1000 DEG C to 1020 DEG C, and the total forging deformation ranges from 50% to 80%; (2) annular part forging is conducted, specifically, the initial forging temperature of cake upsetting and punching forging is 1030-1060 DEG C, and the final forging temperature is 920-940 DEG C; and the initial rolling temperature of the annular part is 1000-1030 DEG C, the final rolling temperature is 920-940 DEG C, and the deformation is 20-40%. According to the method for refining the grain size of the GH2907 alloy annular forge piec