Under thermally activated deformation condition extensive formability may be obtained. In this paper, elevated-temprature formability and tube forming process [1] were analyzed. Two most typical tube forming process, tube free expansion and in-die bulge forming, were simulated by FEA with the use of Abaqus/Standard code. An empirical material equation was used that takes into account bothe starain handening and strain rate heardening effects, to reflects, to reflect material characteristics at high strain rates and at elevated tempratures. For tube free expansion forming, the deformation path was varied by changing the end velocity with respect to internal gas pressure, thus providing an assessment of material forming limit at various strain path. Falure to may occur due to necking and bucking, which are related tko the ratio of internal pressure and end-load. The deformation process and limit strain were obtained for various meterial parameters, including n-value and m-value, as well as the tempreture distribution. The effect of tube gemetry (diameter, thickness and heating length) on the process is also investigated. For in-die tube forming process, the effect of die friction on the material flow and strain distribution was analyzed, and the thickness distributions in the longitudinal direction (for axi-symmetrical tube forming) and in the circumferential direction (for round-to-squared tube forming) were predicted as function of forming parameters. A comparison between prediction and experiment was provided.

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