Groove for longitudinal and circular seams of large-diameter vessel and welding method

Abstract

The invention discloses a groove for longitudinal and circular seams of a large-diameter vessel and a welding method. The existing large-diameter thick-wall 347H type pressure vessel has crack phenomenon in the operation process in a high-temperature and high-Cl<-> environment. The double-side U-shaped grooves are welded to the inner side and the outer side of the vessel, a groove gap is reserved between the U-shaped grooves in the two sides, a groove is machined in a vessel barrel, and surfacing is conducted in the groove; and the two sides of the U-shaped grooves are of an unequal-thickness structure, and the depth of one side of the deep U-shaped groove is 0.6-0.7 time of the wall thickness of the vessel. The invention discloses the groove for the longitudinal and circular seams of the large-diameter vessel and the welding method.

Description

technical field [0001] The invention relates to a bevel and welding method for longitudinal and circular seams of large-diameter containers. Background technique [0002] When the working temperature of the large-diameter thick-walled pressure vessel is higher than 525°C, and the medium in the vessel has a relatively high concentration of Cl - Time. Considering the calculation of allowable stress and the use of medium, nickel base (INCONEL 600 or INCONEL 800, etc.) is generally selected as the material of the main shell of the pressure vessel. In recent years, in order to reduce the cost of use, under the same working conditions, design institutes began to gradually choose 347H high-carbon austenitic stainless steel containing stabilizing elements to replace nickel-based materials. Although the use of 347H stainless steel reduces the cost of raw materials by about 50%-60%, but the 347H pressure vessel is - Under the dual action of the product welds, penetrating cracks oft...

AI Technical Summary

Problems solved by technology

Although the use of 347H stainless steel reduces the cost of raw materials by about 50%-60%, but the 347H pressure vessel is - Under the double action of the product welds, penetrating cracks often appear during the operation process. The preliminary analysis is the cracks caused by stress corrosion, and its occurrence is also closely related to the groove selection in the product manufacturing process.

The core equipment of a domestic raw material production line has used a large number of 347H as the main shell material, and the cracks in the longitudinal and annular seams of the shell have a high proportion, which seriously affects the production of the product

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