Tula State University, Tula, Russia:

S. N. Larin, Professor, Department of Mechanics of Plastic Forming, e-mail: mpf-tula@rambler.ru
V. I. Platonov, Associate Professor, Department of Mechanics of Plastic Forming
V. A. Korotkov, Senior Researcher, Department of Mechanics of Plastic Forming

This work investigated the problems of regulation of the kinematics of the flange flow in the preparation of hollow cylindrical shells with the use of round billets with elimination of the formation of festons during stamping of materials at both normal and elevated temperatures with any kind of planar anisotropy. In the classical drawing operation of a circular workpiece, two, four, six, eight and twelve festoons of different heights can form on the upper edge of the resulting semi-finished product due to the presence of initial anisotropy in the sheet material. The technological process provides pruning of the resulting festons, which requires assignment of allowances in the initial round billet, thus increasing the waste material and the cost of shells. One of the existing methods of eliminating the feston formation during drawing is the use of profiled semifinished products. However, to construct a contour of such a profile products, information is needed on the anisotropy coefficients determined from the tensile test of samples sectioned at different angles to the rolling direction. Each new batch of sheet materials arriving for production can have different values of the anisotropy coefficients, therefore, it is necessary to conduct mechanical tests with each new arrival, which is very laborious. To reduce the complexity of determining the initial anisotropy of sheet metal, it is proposed to use the procedure for the experimental determination of the height of the festons and their location relative to the direction to rolling after technological tests in the conventional drawing matrix. To produce hollow cylindrical shells of anisotropic materials, it is proposed to use a drawing template with a profiled input part in the form of a set of removable rings or sections, which allows controlling the kinematics of the flow of the flange part of the round billet, taking into account the known characteristics of the planar anisotropy of the material, and obtain after drawing the shell without festons, normal temperature, and isothermal stamping.

1. Yakovlev S. P., Yakovlev S. S., Andreychenko V. A. Pressure treatment of anisotropic materials. Chisinau : Quantum, 1997. 331 p.
2. Forging and stamping : handbook. In 4 volumes. Vol. 4. Sheet metal stamping. Ed.: Yakovleva S. S. Moscow : Mashinostroenie, 2010. 732 pp.
3. Storozhev M. V., Popov E. A. Theory of metal forming. Moscow : Mashinostroenie, 1977. 423 p.
4. Nechepurenko Yu. G., Yakovlev S. P., Yakovlev S. S. Deep drawing of cylindrical products of an anisotropic material. Tula : TulGU, 2000. 195 p.
5. Popov E. A. Foundations of the theory of sheet punching. Moscow : Mashinostroenie, 1977. 278 p.
6. Yakovlev S. S., Tregubov V. I., Nechepurenko Yu. G. Deep drawing of anisotropic hardening material. Zagotovitelnye proizvodstva. 2005. No. 4. pp. 38–44.
7. Yakovlev S. P., Chudin V. N., Yakovlev S. S., Sobolev Ya. A. Isothermal deformation of high strength anisotropic metals. Moscow : Mashinostroenie, Izdatelskiy dom TulGU, 2003. 427 p.
8. Mousavia A., Kunzeb T., Rochb T., Lasagnib A., Brosius A. Deep drawing process without lubrication — an adapted tool for a stable, economic and environmentally friendly process. Procedia Engineering. 2017. Vol. 207. pp. 48–53.
9. Tennera J., Andreasa K., Radiusa A., Merklein M. Numerical and experimental investigation of dry deep drawing of aluminum alloys with conventional and coated tool surfaces. Procedia Engineering. 2017. Vol. 207. pp. 2245–2250.
10. Senyong Ch., Yi Q., Chenb J. G., Chee-Mun Ch.. A forging method for reducing process steps in the forming of automotive fasteners. International Journal of Mechanical Sciences. 2018. Vol. 137. pp. 1–14.
11. Junsong J., Xinyun W. L., Deng J. L. A single-step hot stamping-forging process for aluminum alloy shells parts with nonuniform thickness. Journal of Materials Processing Technology. 2016. Vol. 228. pp. 170–178.