Preparation method and application of composite pipe

Abstract

The invention discloses a preparation method and application of a composite pipe. The preparation method of the composite pipe comprises the steps of carrying out surfacing on the outer surface of a base pipe, and carrying out mechanical rolling polishing to form a composite layer. The surfacing is spiral surfacing; and the inter-channel lap joint rate of the surfacing is larger than or equal to 70%. According to the preparation method of the composite pipe, the binding force of the composite layer and the base pipe can be increased, and the depth of surfacing lines is decreased by adjusting the inter-channel lap joint rate.

Description

technical field [0001] The invention belongs to the technical field of composite pipes, and in particular relates to a preparation method and application of composite pipes. Background technique [0002] Composite seamless pipes can be used to manufacture pressure-bearing equipment such as boilers and pressure pipes, including cladding and base layers. Common materials for base layers are carbon steel, alloy steel and stainless steel, and common materials for cladding layers are stainless steel or nickel-based materials. The amount of composite seamless pipe is small, and it needs to be produced in small batches and high quality according to the size and material required by customers. Therefore, flexible and convenient small batch production is the trend of this industry. [0003] According to the classification in GB 28883 "Composite Seamless Steel Tube for Pressure Bearing", the currently commonly used manufacturing processes for pressure-bearing composite seamless tube i...

AI Technical Summary

Problems solved by technology

The production process is complicated, the molding specifications depend on the mold, the drawing or extrusion process is easy to cause damage to the pipe, the bonding force between the cladding layer and the base layer is poor, the production cost is high, and it is difficult to achieve small batch production

[0007] In summary, in the traditional commonly used composite seamless pipe preparation methods, the molding specifications are very dependent on the mold (shape, size, etc.), and it is difficult to achieve special specification pipe customization during the production process (unless the cost is increased to change the mold), and small batch production is impossible. relatively high production costs

The bond between the composite layer and the base layer is only interfacial diffusion between elements, not a real metallurgical bond, so the bond strength is poor

[0008] As a mature surface modification process, surfacing welding has been widely used in various production fields, which can overcome the defects of the above methods to a certain extent, but the surface of the composite pipe formed by surfacing welding is prone to irregular lines, and dust is easy to accumulate in the lines. Slag and lines are also likely to cause stress concentration, and then break during the pressure-bearing process. In addition, the composite pipe formed by surfacing welding is deformed due to welding stress, and the dimensional accuracy of the pipe straightness is low, especially it cannot be installed in various high-precision boilers. pressure vessels and pressure piping

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