Method for forging thick-walled ring-shaped parts

Abstract

The invention relates to a method for forging thick-walled ring-shaped parts. The method includes the following process steps: step 1: steel ingot sawing; step 2: upsetting and punching; step 3: drawing out on a mandril: the drawing-out ratio is controlled at 1.8 to 2.2; and step 4: secondary upsetting and finishing. Since the method adds the processes of drawing out on the mantril and secondary upsetting after punching, in the process of drawing out on the mantril or reaming, the effective wall thickness of the forging is already quite small, pressure can be easily transferred to the central part of the forging during forging, the deformation pressure can deform the core of the billet due to the great reduction of the effective forged thickness, moreover, the core receives pressure stress in three directions, the as-cast structure of the steel ingot is changed, in-situ pores are forged to be closed, the defects of segregation and inclusion are improved, and thereby the internal quality of the forging is greatly improved.

Description

technical field [0001] The invention relates to a method for forging a thick-walled ring. It belongs to the field of forging technology. Background technique [0002] 1. Common problems of thick-walled ring forgings [0003] For thick-walled ring parts with a wall thickness greater than 500mm and a height greater than 450mm, the pass rate of ultrasonic flaw detection is low, and it shows that the larger the diameter of the forging and the heavier the tonnage, the less likely it is to pass the ultrasonic flaw detection. According to the experimental analysis, the ultrasonic flaw detection of such products is unqualified, mainly because the as-cast structure in the forging has not completely changed, and there are defects such as dendrites, looseness, and segregation. These defects are accompanied by non-metallic inclusions, forming so-called tiny pores and cracks. , resulting in unqualified ultrasonic flaw detection. The reason is that the internal compressive stress and d...

AI Technical Summary

Problems solved by technology

[0004] 2. The original forging process and existing problems

Although the forging ratio is large enough (up to 3.5~7) using this process method, due to the RST effect Excessive upsetting ratio is not conducive to the improvement of internal quality. Ultrasonic flaw detection often finds that there are dense excessive defects inside forgings.

[0006] The pass rate of ultrasonic flaw detection of thick-walled ring forgings produced by this process is low, and the quality is difficult to guarantee

Images