Composite stack-up type stirring friction welding additional material forming technology of large-scale thick-wall cylindrical piece

Abstract

The invention discloses a composite stack-up type stirring friction welding additional material forming technology of a large-scale thick-wall cylindrical piece. The forming technology comprises the following steps: first, carrying out roll forming on a thin-wall annular piece monomer; then, carrying out radial stack-up type stirring friction welding additional material forming on the thin-wall annular piece monomer to finish the forming process of a first thin-wall annular piece monomer radial stack-up type stirring friction welding additional material of a first layer; then, carrying out axial stack-up type stirring friction welding additional material forming technology on the thin-wall annular piece monomer, and carrying out axial superposition welding on a third thin-wall annular piece monomer of a second layer and the first thin-wall annular piece monomer; then, carrying out radial and axial stack-up type stirring friction welding additional material forming technology on the thin-wall annular piece monomers, and carrying out radial and axial welding on a fourth thin-wall annular piece monomer, the second and third thin-wall annular piece monomers of the second layer; and finally, carrying out radial, axial and radial and axial composite stack-up type stirring friction welding additional material forming on the thick-wall cylindrical piece. With adoption of the forming technology, the material utilization ratio is remarkably increased, the energy consumption is reduced, and the overall performance of the product is improved.

Description

technical field [0001] The invention belongs to the technical field of forming large thick-walled cylindrical parts, and in particular relates to a composite layered friction stir welding additive forming process for large thick-walled cylindrical parts. Background technique [0002] With the rapid development of my country's petrochemical, nuclear power and other large-scale equipment, large-scale has become a key development trend in related fields. Large cylindrical parts are one of the main types of large forgings. They are widely used in thermal power, nuclear power, petrochemical and other industrial fields. With the rapid development and technological progress of these industries, the demand for large cylindrical parts is becoming more and more extensive. As an important part of these container equipment, large cylindrical parts have higher and higher comprehensive performance requirements. In addition, their ultra-large size poses greater challenges to production and...

AI Technical Summary

Problems solved by technology

As an important part of these container equipment, large cylindrical parts have higher and higher comprehensive performance requirements. In addition, their ultra-large size poses greater challenges to production and manufacturing.

For a long time, the free forging process has been adopted in the production of large cylindrical parts in my country, which not only has low production efficiency, but also has large deviations in shape and wall thickness, and consumes a lot of energy and materials.

Since the forming process requires a huge forming force to complete, it is difficult to manufacture large-scale forging equipment, and the manufacturing cost is high. Due to the limitation of the forming capacity of the press and the forming quality of the product, it is difficult to achieve its forming with forging technology.

With the increase of the ingot, the solidification speed is slow, the material segregation is serious, the grains are coarse and the crack casting defects cannot be completely eliminated in the later forging process, resulting in part of the elongation and strength not meeting the design requirements.

In actual production, it is very easy to have phenomena such as skin clipping, cavity filling, and coarse grains.

Moreover, the successful forging of large cylindrical parts is often at the cost of more material loss and higher energy consumption.

In addition, the existing friction stir welding is easy to form defects such as flash, pit and keyhole at the weld

Therefore, the traditional processing methods for large thick-walled cylindrical parts can no longer meet the market's high-efficiency, energy-saving and material-saving manufacturing requirements, and superior performance.

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