Multi-pass rolling-extrusion of large-scale thin-walled square tube with longitudinal inner ribs

Thin-walled square tube with longitudinal rib (TWSTILR) is a key structural component widely used in aerospace field. However, there are still critical problems in the preparation of large-scale TWSTILR component due to their complex shapes and structures. Components prepared by traditional low-efficiency, high-cost separate manufacturing, and cutting forming processes are difficult to meet service requirement. Therefore, this article proposes to break through the technical bottleneck of the integral forming of such TWSTILR components by preformed rib method and multi-pass rolling-extrusion process. This article mainly elaborated the design method of preformed rib and the principle of multi-pass rolling-extrusion. And the metal flow deformation behavior and equivalent strain distribution of typical region of TWSTILR workpiece during multi-pass rolling-extrusion process were revealed by finite element simulation. In addition, the effects of different process parameters on TWSTILR forming were discussed. Finally, the physical forming experiment was designed and implemented, which fully verified the feasibility of the forming process for preparing TWSTILR component.

Automated summary

This study proposes a new method for preparing thin-walled square tubes with longitudinal ribs by breaking through the technological bottleneck of integral forming using preformed ribs and multi-pass rolling-extrusion process. Finite element simulation is used to reveal the metal flow deformation behavior and strain distribution, while a physical forming experiment verifies the feasibility of the proposed forming process.