Forging process for large shaft parts

Abstract

The invention discloses a forging process for nuclear power rotor and other large shaft parts, which can be used for effectively solving the forging problem of a high-grade rotor with a super large specification. The process specifically comprises the following steps of: (1) drawing out a steel ingot to form a flat square by using a WHF (Wide die Heavy blow Forging) method; (2) performing erecting and upsetting on the flat square; (3) drawing out the upset steel billet to the flat square again by using the WHF method; and (4) compacting the four sides and the center of the flat square, wherein the 'flat square' specifically means a cuboid-shaped steel billet. In accordance with the result of flaw detection (UT(Ultrasonic Test) and MT (Magnetic particle Test)), no flaw (phi is above 0.6), for which recording is required, is found in a 1100MW rotor piece manufactured by using 550t steel billets, and the quality is superior; based on the dimension of a workpiece, all the dimensions of various parts of a forge piece can meet the processing requirement, and the forging allowance is uniform; the control state of forging grain size is deduced from a UT state subsequent to thermal treatment after forging, the desired effect is completely achieved, and no phenomenon of coarse crystal or mixed crystal happens.

Description

technical field [0001] The invention relates to a shaft part, especially a forging process of super-large and high-grade nuclear power rotors. Background technique [0002] In the past, the forging process for conventional nuclear power rotors was as follows: [0003] 1) Cut off the ingot tail of the steel ingot, and press the jaw on the riser end of the steel ingot; [0004] 2) After the sleeve is put on the jaws, a single driving operation is used to perform one or more upsetting of the steel billet; [0005] 3) Rolling and drawing to lengthen the material; [0006] 4) Trim and produce the finished rotor. [0007] However, when the applicant of this application used the above-mentioned process to produce the first 1100MW nuclear power rotor in China (the total length of the part is 15226mm, and the maximum cross-sectional diameter is φ1955mm), he found that the above-mentioned conventional rotor forging technology is not suitable for the production of super-large and hi...

AI Technical Summary

Problems solved by technology

The disadvantage of this method is that it is limited by the space of the hydraulic press, and the number of pulling trips is less, and the second is that the heating effect before upsetting does not increase.

[0010] 3) Due to the large size of the forging, the operation is difficult, and the workload of each fire is limited, so the deformation is difficult to synchronize

[0013] like Image 6 As shown, the existing "central compaction method" is to place the flat square 7 on the lower wide anvil 9 and forge it through the upper narrow anvil 8, and only one side of the flat square 7 can be operated at a time

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