Cold Extrusion of Flanges on Cylindrical Hollows
Flanges on hollow cylindrical engineering components are often made by free upsetting when under certain conditions a bulge is formed in the unsupported portion, which on further deformation appears as a fold in the finished flange.
The alternative method of flange extrusion has been investigated for producing flange at the end, or away from the end of tubes. The results show that folds in the flange are often present, albeit in a reduced size under favourable conditions. The penetration of the fold or folds is greater into thicker flanges and are often accompanied by a defect in the bore of the tube which has a crack-like appearance. The diameter of the flange is uneven and its shape can be irregular. Particularly thinner flanges often obtain a dished shape, which becomes more pronounced as the diameter of the flange increases.
An upper bound method developed to predict extrusion pressures agreed well with experiments over particular flange tickness/tube wall thickness ratios.
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- 2.J.M. Alexander and B. Lengyel (1964) On the Cold Extrusion of Flanges Against High Hydrostatic Pressure. J. Inst. Metals, 93, p. 137Google Scholar
- 3.H. Ll. D. Pugh (1965) Recent Developments in Cold Forming. Bulleid Memorial Lectures, Vol. IIIA, p. 27.Google Scholar
- 6.P.F. Thomason (1968) The Use of Pure Aluminium as an Analogue for the History of Plastic Flow, in Studies of Ductile Fracture Criteria in Steel Compression Specimens. Int. J. Mech. Sci., 10, p. 501.Google Scholar
- 8.A.T. Male and M.G. Cockroft (1965) A Method for the Determination of the Coefficient of Friction of Metals under Conditions of Bulk Plastic Deformation. J. Inst. Met., 93, p. 38.Google Scholar
- 9.B. Avitzur (1968) Metal Forming Processes and Analysis. McGraw-Hill, p. 78.Google Scholar