A connection method of pressure vessel nozzle and head to reduce welding residual stress

Abstract

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. It is characterized in that it includes the following steps: a. drilling the head and processing the connecting pipe (2); b. extending one end of the connecting pipe (2) into the pressure vessel (1); c. welding the sealing head and the connecting pipe (2); d. Preheat the welding seam (3) on one side of the pressure vessel (1), and then surfacing welding at the root of the connecting pipe (2) in the pressure vessel (1); e. After preheating the inner wall of the connecting pipe (2) Then surfacing welding on the inner wall of the connecting pipe (2); f, cutting the connecting pipe (2) in the pressure vessel (1); g, tempering the head. The pressure vessel nozzle and head connection method for reducing welding residual stress reduces the welding residual stress during the pressure vessel manufacturing process, improves the structural integrity of the pressure vessel, and enhances the stress corrosion cracking resistance of the pressure vessel nozzle welded joint.

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.

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