Connecting method of pressure vessel connecting pipe and sealing head for reducing welding residual stress

Abstract

The invention relates to a connecting method of a pressure vessel connecting pipe and a sealing head for reducing welding residual stress, which belongs to the technical field of sealing container processing and manufacturing. The connecting method is characterized by comprising the following steps of (a) opening the sealing head, and processing the connecting pipe (2); (b) extending one end of the connecting pipe (2) into a pressure vessel (1); (c) welding the sealing head and the connecting pipe (2); (d) preheating one side, which is positioned in the pressure vessel (1), of a welding seam (3), and then performing overlay welding on the root of the connecting pipe (2) in the pressure vessel (1); (e) preheating the inner wall of the connecting pipe (2), and then performing overlay welding on the inner wall of the connecting pipe (2); (f) cutting the connecting pipe (2) in the pressure vessel (1); (g) tempering the sealing head. According to the connecting method of the pressure vessel connecting pipe and the sealing head for reducing the welding residual stress, the welding residual stress is reduced in the manufacturing process of the pressure vessel, so that the structural integrity of the pressure vessel is increased, and the stress corrosion cracking resistant capability of a welding connector of the pressure vessel connecting pipe is enhanced.

Description

technical field [0001] The invention discloses a method for connecting a pressure vessel nozzle and a head for reducing welding residual stress, and belongs to the technical field of sealing vessel processing and manufacturing. Background technique [0002] As a pressure-bearing equipment, pressure vessels are widely used in petrochemical, pharmaceutical, aerospace, nuclear power and other industries. The head of the pressure vessel contains a large number of T-shaped joints, and the joints and the head of the pressure vessel are connected by welding. However, welding inevitably introduces residual stress. The existence of welding residual stress has a great influence on stress corrosion cracking. Stress corrosion will cause the pressure vessel to rupture when the stress is lower than its strength limit. Therefore, it is of great significance to effectively reduce the residual stress at the welded joint of the T-shaped joint to ensure the safe operation of the pressure vess...

AI Technical Summary

Problems solved by technology

At present, the methods for reducing welding residual stress are mainly divided into two categories: post-weld heat treatment and mechanical action method: post-weld heat treatment consumes a lot of energy and time, is not suitable for large pressure vessels, and the residual stress cannot be fully eliminated; and It is difficult to eliminate the residual stress of the T-joint by the mechanical action method, and the operation is inconvenient

Both post-weld heat treatment and mechanical action are carried out after the pressure vessel is manufactured. This elimination method not only wastes time, but also requires a lot of manpower and material resources, which is not in line with high-efficiency production.

Images