Testing a new technique for producing artillery cartridge cases from pipe workpiece by roughing with a friction tool

Abstract

The object of this study is the technological process of manufacturing parts such as artillery shells using pressure treatment methods. The work is aimed at solving the current scientific and technical task to improve the technological processes for manufacturing parts such as cartridge cases based on the use of a tangential rolling operation with a friction tool, which ensures the production of hollow products with a bottom. Using the finite element method, modeling of the bottom rolling processes was carried out, which made it possible to establish the effective geometry of the processed workpieces and their heating temperature. Recommendations have been devised for the design of new technological processes for roughing bottoms, which consist of determining the wall thickness of the workpiece before deformation, the heating temperature of the workpieces, and the amount of supply of the workpiece to the friction tool. The resulting recommendations were verified by experimental studies. Roughing of spherical bottoms should be carried out for pipes with a relative wall thickness (D/s) in the range of 15...20, the homologous heating temperature should be 0.8, and the relative feed of the workpiece into the friction tool should be 0.9. Testing the established relationships under laboratory conditions confirmed the recommendations for changing the shape of spherical bottoms during the roughing process. The results of metallographic studies on full-scale products confirm the results of the theoretical study. It is recommended to use this technique for products that have an axial hole (artillery shells, hydraulic cylinders, etc.), which will allow removing axial defects in the bottom after drilling the axial hole. The results could be used at machine-building enterprises in the manufacture of dual-use parts