Method for producing circular cog hot forged from generator protective ring and mould

A generator and hot forging technology, applied in the direction of manufacturing tools, forging/pressing/hammering machinery, household appliances, etc., can solve problems such as poor stress state, difficulty in removing defects, and easy cracking, to solve the problems of easy cracking, Improve plasticity and improve lubrication effect

CN1736630AInactive Publication Date: 2006-02-22DEYANG WANXIN POWER STATION PROD DEV
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Patent Information

Authority / Receiving Office
CN · China
Current Assignee / Owner
Publication Date
2006-02-22
Estimated Expiration
Not applicable · inactive patent

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Abstract

The invention discloses a method and the die for preparation of a hot forging ring billet of the guard ring of generator, and relates to a forging technique and the device of guard ring part of generator. The prior hot forging technique is flat-die forging, easily to produce crack in the process. The invention using confined shaping in die instead of flat-die forging, it improves the state of stress and prevents the crack effectively. With the symmetry of sphere plunger axis in the process of fan boring, the crystal particles are fine and uniform, which provides a perfect condition for cold strain intensification. With the jacket shaping of billet, it can improve lubrication and decrease friction, and can keep the temperature of the hot billet effectively, improving the plasticity and decreasing the shaping pressure. The invention solves the three problems that the crack is easy to produce, the structure property is not uniform, and the shaping pressure is large; compared with the prior technique, the invention has a projecting progress and a distinctive effect.
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Description

Technical field

[0001] The invention belongs to the field of metal plastic forming and relates to a forging process of generator retaining ring parts. Background technique

[0002] Retaining ring is one of the large key parts in thermal power generation equipment. It not only bears huge centrifugal force during high-speed rotation, but also bears thermal loading stress, alternating stress, and bending stress. It requires sufficient strength, good toughness, uniform mechanical properties, and minimum residual stress. Moreover, the guard ring works in a strong magnetic field and corrosive atmosphere. Therefore, it is also required to be non-magnetic and have high stress corrosion resistance. At present, the method of manufacturing retaining ring parts at home and abroad generally adopts the heating and forging of steel ingots into annular blanks (hot forging), and then solid solution treatment and cold deformation strengthening (cold forging) into forgings, and finally machining. ...

Examples

Embodiment Construction

[0029] Specific implementation plan

[0030] The 300MW generator retaining ring is selected as the implementation object. The finished forging is a cylindrical part. The retaining ring material is Mn18Cr18N steel. The heating specification is: the initial forging temperature is 1150~1200℃, and the final forging temperature is 950~1000℃.

[0031] Stamping step: the billet is drawn by the steel ingot into a cylindrical shape, the diameter D=850mm, and the billet height is 1000mm. Expansion and extrusion forming step: the amount of expansion and extrusion deformation is 70mm, and the ratio of expansion and extrusion deformation is 1:1. Under this condition, after calculation, the dimensions of the ring blank after two expansions can be obtained: φ950×φ540×1050mm, φ1000×φ640×1050mm.

[0032] The sheath material is No. 15 steel, the thickness is 30mm, and the mold material is H-13 steel. The inner wall of the drum mold has a draft angle.

[0033] Such as figure 1 , 2 , 3, 4, and 5, a ...