Analysis and experimental study of patch tube mechanical properties based on screen pipe hydroforming patch technology

Abstract

Hydroforming patch technology for damaged screen pipes is designed based on tube hydroforming technology, and the methods for determining the forming pressure range and forming defects are selected according to the forming process. The hydroforming patch model for screen pipes is established according to the technical demand parameters for screen pipe repair. From the mechanical properties of the material and digital–analog comparison analysis of the material formability, it is found that the determiners for formability (such as forming pressure, thinning rate, and springback) of 321 stainless steel (SS321) are better than those of 304L stainless steel (SS304L), and the patch tube materials meeting the technical requirements were selected. A test bench for the formability of patch tubes was built to verify the forming pressure of patch tubes with different thicknesses and the distribution of wall thickness after forming. The results show that the hydroforming patch technology is feasible and can realize the firm and close fit between the patch tube and screen pipe; moreover, SS321 can meet the material requirements of the patch tube.