The invention relates to a
shape control method for a casing
forge piece for a large gas
turbine. The
shape control method comprises the following steps that S1, blanking is conducted; step S2, chamfering is carried out; s3, upsetting and
punching are carried out; s4, cooling after
forging; s5, primary annealing is conducted, and heat preservation is conducted on the forged piece at the temperature of 690 + / -40 DEG C; s6, trestle chambering is conducted, and the
forging temperature ranges from 900 DEG C to 1150 DEG C; s7, secondary annealing is conducted, specifically, the forged piece is annealed and subjected to heat preservation, and the annealing temperature is 690 DEG C + / -40 DEG C; step S8, normalizing: normalizing the
forge piece and preserving heat at the normalizing temperature of 1130 + / -5 DEG C; s9, primary
tempering is conducted, specifically, the
forge piece is tempered and subjected to heat preservation, and the
tempering temperature is 760 + / -5 DEG C; s10,
quenching is conducted, specifically, the forge piece is quenched, and the
quenching temperature is 1120 + / -5 DEG C; s11, secondary
tempering is conducted, specifically, the forge piece is tempered, and the tempering temperature is 680 + / -5 DEG C; and S12,
stress relief annealing is conducted, and the
stress relief annealing temperature is 630 + / -5 DEG C. The method has the advantages that the performance stability is improved, and the
cracking phenomenon of the product caused by
stress concentration is avoided to the maximum extent.