A processing method for a head of a pressure vessel

Abstract

The invention relates to a method for processing a head for a pressure vessel. The inner shape of the head for a pressure vessel is an ellipsoid or a spherical surface. The inner shape processing method adopts a special head inner shape processing fixture and places it on a lathe. On the turntable, the inner shape of the end frame of the head inner shape processing fixture for the pressure vessel is aligned, and then the inner shape surface is processed by turning until the inner shape surface meets the preset requirements. The outer shape processing method uses a special head shape processing jig and places it on the turntable of the lathe to align the inner shape of the end frame of the head shape processing jig for pressure vessels. After that, the inner shape surface is processed by turning until the inner The shape and surface meet the preset requirements. The invention improves the processing accuracy, processing efficiency and dimensional stability of the head used for the pressure vessel.

Description

technical field [0001] The invention relates to a method for processing a head used for a pressure vessel, and belongs to the technical field of mechanical processing. Background technique [0002] Heads for pressure vessels are generally formed by spinning. The traditional spinning process can be divided into shear spinning and ordinary spinning. In the process of shear spinning, the thickness of the slab follows the sinusoidal law, and the thinning rate increases with the decrease of the shear spin angle α, which will make the wall thickness uniformity of the spherical head part poor; in the ordinary spinning During the process, the contraction or expansion of the diameter of the slab causes slight corrugations on the flange edge, and the corrugation hinders the forming of the rotary wheel, which increases the tensile stress of the billet during forming, causing the metal in the active area of ​​the rotary wheel to appear thinner. The formed components often have a certa...

AI Technical Summary

Problems solved by technology

[0005] The head of the pressure vessel generally adopts the process method of welding the ring with multiple melon petals, and then welding with the top cover, transition ring and other parts. This method has a large number of welds, and the manufacturing process of parts and components is long, complicated and inefficient.

[0006] 2. Lack of interchangeability of products

On the other hand, the unevenness of the manual inspection gap also has a certain impact on the welding quality

Due to the low manufacturing precision of parts and components, a large number of matching and repairing work in the assembly process is caused, and the lack of interchangeability seriously affects manufacturing efficiency.

[0008] 3. The number of welds is large and the product reliability is low

Compared with the base metal, the mechanical properties and corrosion resistance of the weld position are lower than those of the base metal due to the presence of welding defects, welding residual stress, and microstructure changes due to thermal cycles, and its performance can only reach the maximum of the base metal. 90% of the total, the overall reliability is poor, and it is difficult to meet the quality requirements of aerospace high reliability

At the same time, the manufacturing precision of components and the welding and assembly precision of the box are not high, and the existence of gaps and seams leads to poor weld performance and uneven force, which can only be covered by increasing the design margin, which is not conducive to the realization of light weight structure efficient target

[0010] The above problems seriously affect the manufacturing efficiency, accuracy and reliability of pressure vessel head products in the aerospace field

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