Forging bearing straight three-way production method

Abstract

The invention relates to a pipeline for pressure vessels, in particular to a method for manufacturing high-pressure and high-temperature resistance large straight-tees. The method comprises the following steps: preparing the blank to be forged; then carrying out the molding treatment of the straight-tee main and branch holes, wherein the molding treatment is carried out by forging punching holes and enlarging holes, and when forging the punching holes, the position of the center line of the main hole forged deviates from the position of the center line of the blank; and finally, carrying out after-forging treatment, including the re-treatment of the main hole and the branch hole. The method has the advantages of replacing the status of the imports all year round, reducing the cost of production, greatly saving the manpower and time, and decreasing the processing period. Furthermore, the method uses the forged punching, thereby eliminating the defect that the material inside the solid core of the large billet is loose, and significantly improving the mechanical performance of the product when tested by the United States ASME SA182 standard.

Description

Technical field [0001] The invention relates to pressure vessel pipes, in particular to a method for manufacturing a large-scale straight three-way that is resistant to high pressure and high temperature. Background technique [0002] Large straight tees are mainly used for tees such as large boilers and pressure vessel pipes. They are resistant to high pressure (≥30MPa) and high temperature (≥500℃). As forgings, they are the highest grade (grade 5) free forgings on the hammer, with large volume and shape. Complex, the required state of the main hole for punching and forming is technically quite complicated. The use requirements include "normal", "abnormal", "emergency" and "accident" and other different operating conditions of the consequences and the degree of harm to determine its inspection standards, the production of such forging products is quite difficult. [0003] At present, the product is mainly dependent on imports. The large straight tee imported from abroad is forge...

AI Technical Summary

Problems solved by technology

[0002] Large straight tees are mainly used for tee joints such as large boiler pressure vessel pipes. They are resistant to high pressure (≥30MPa) and high temperature (≥500°C). As forgings, they belong to the highest level (level 5) hammer free forgings. They are large in size and shape. Complicated, the state required for the stamping of the main hole is technically quite complicated

The use requirements include "normal", "abnormal", "emergency" and "accident" to determine the consequences and hazards of different working conditions. It is quite difficult to produce such forgings.

[0003] At present, this product mainly relies on imports. The large-scale straight tees imported from abroad are forged from a single piece of material, and the main hole and branch holes are directly processed according to the drawing size by turning. The main thing is that it is difficult to eliminate the internal looseness caused by the thickness of the material when forging a large piece of steel, which will inevitably affect the product quality to a certain extent.

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