关键词: 管材, 液压胀形, 胀形性能

Abstract: Material properties have great effect on the hydro- bulging process and quality of the formed tube，while the material properties obtained from the common tensile test differ from bulge formability of a tube. A simple and practical test tooling is developed for hydro-bulging test of tubes with varied materials and sizes. As a test stands alone in hydro-bulging formability, the tooling can be worked on a conventional press, even on a single action press. It has no use for any external hydraulic pressure source, but an internal one replaces that serves as a pressurized fluid supplier by which the internal pressure and axial load required for hydro-bulging can be automatically and synchronously provided. The ratio of the two loads can be achieved by proper design of the fluid supplier. Free expansion bulging, bulging with axial feed, free and restrained bulging (free and fixed ends) can be fulfilled by the tooling, and bulging with proportional loading to some extension can be realized. A series of bulging experiments on the tooling display that restrained conditions on tube ends highly affect the free expansion bulging, while the internal pressure, axial load and ratio of two loads highly affect the bulging with axial feed.

Key words: Bulging formability, Hydro-forming, Tube