Forging process of plate element

Abstract

The invention discloses a forging process of a plate element with better processing quality. The process is characterized by comprising the following steps of: upsetting and punching a steel ingot and then forging the formed blank into a barrel-shaped intermediate blank; then splitting the barrel-shaped intermediate blank and then flattening to form a plate blank; and finally obtaining a finished product by cutting on the plate blank. In the invention, through forging the blank into the barrel-shaped intermediate blank to realize the axial-enlarging deformation mode of the blank, instead of a axial-upsetting deformation way, a laminated defect easily occurring when a cake-shaped part is forged is avoided, and the forging penetration performance is better; a forging tissue with more compact inner and outer surfaces is reserved by utilizing the finished product cut from the plate blank with uniform deformation and coincident final forging temperature, which is more beneficial to crystal grain refining and crystal grain uniformity and fully ensures the special requirement for the quality of a forging part; and in addition, the process also effectively avoids rigidity nonuniformity caused by the radial C segregation of the steel ingot. Thus, through the process, the processing quality of the product can be markedly improved, and the processing requirement of a large mirror plate or an end sealing plate blank is satisfied.

Description

technical field [0001] The invention relates to the field of forging, in particular to a forging process of a plate. Background technique [0002] The "plate" mentioned in this application includes a pie-shaped piece with or without holes. Its general D / H (ratio of outer diameter to height) ≥ 15. For example, mirror plates for hydroelectric generators, head slabs for pressure vessels, etc. [0003] Taking the large mirror plate in a 700MW hydroelectric generator set as an example, its outer diameter is close to 5500mm, its inner diameter is close to 4000mm, and its thickness is close to 150mm. Such as Figure 1-7 As shown, the existing forming process for the mirror plate includes the following steps: a. Upsetting and punching the steel ingot 1 to form a blank; b. Reaming the blank so as to maintain the blank while increasing the inner and outer diameter of the blank. The thickness in the axial direction is basically unchanged, and then it is flattened in the axial direct...

AI Technical Summary

Problems solved by technology

The disadvantages are as follows: 1) Since the axial thickness of the blank tends to decrease as a whole, in step c, due to the small axial thickness of the blank, the overall warping deformation is prone to occur during stretching, because the mirror plate and the head The outer circle of the slab is large and thin, and it is difficult to correct after deformation

2) In step c, due to the large outer diameter of the billet, it is impossible to upset as a whole, so only rotary expansion and pressing can be used, but the rotary operation is difficult, the terminal temperature of the mirror plate and the end surface of the head slab are inconsistent, and it is easy to coarse grain and mixed crystal

3) When the billet is forged into a cake shape, it is easy to produce layered defects

4) Due to the existence of radial C segregation of large steel ingots, the use of this forming method will lead to uneven hardness on the same end face

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