Stamping a medium – sized cartridge blank from low – carbon steel

Abstract

The work is devoted to obtaining a medium – sized cartridge blank from low-carbon steel. The sequence of punching transitions includes a hot back- extrusion operation, two cold draw – thinning operations, and a cold crimp operation. Modeling using the finite element method established: efforts and specific forces during operations, thermal effect during shaping, shape and size of semi – finished products with distributions of strain intensity. An elastoplastic metal model was used, which made it possible to reveal the forces of extracting the tool from deformed semifinished products and the forces of removing semifinished products from the matrix. A hollow semifinished product with the required dimensions of a protrusion on the bottom part from the side of the cavity and a protrusion on the end for forming a flange is obtained by reverse extrusion. The possibility of carrying out the first drawing operation with thinning through three sequentially located matrixes is shown. After this operation, annealing of the semi-finished product is required to restore plasticity. In the second operation of drawing with thinning and additional stamping of the bottom part, the final dimensions of this part from the side of the cavity and the shaping of the flange on the lateral surface of the semi-finished product are provided with the creation of a macrostructure to ensure the required operational properties. The shape and dimensions of the wall of the semi-finished product after the second drawing, the distribution of the intensity of deformations in it are determined from the condition of reaching the final dimensions and mechanical properties of the cartridge blank at the last crimping operation. For this, the deformations obtained as a result of the second drawing are taken into account when modeling the crimp. The proposed technology for stamping a blank of a sleeve can be implemented on a universal press – forging equipment, has a high productivity and minimizes mechanical processing.

Corrugation prediction in process of sheet drawing based on the results of modeling in the DEFORM environment

“…Враховуючи неоднозначні рекомендації щодо застосування притискача для другої витяжки можливість отримання деталі за два операції та необхідність застосування притискача на кожній з них перевірялась шляхом чисельного моделювання процесів в програм-ному комплексі Deform 3D [8], який ефективно використовується як для моделювання процесів об'ємного [9][10][11], так і листового штампування [12][13][14].…”