Energetical theory of metal processing as the basis of the calculating resource-saving sequences method of wire-drawing

The calculation formulas for determining the power spent on the process of wire drawing in a monolithic die based on the energy method for solving technological problems of metal forming are obtained in this article. The founder of this method is V.N. Vydrin. The power of electric energy was converted by an electric motor into mechanical energy and supplied to the block of a drawing mill by reducer. It is spent on overcoming the friction forces in a monolithic drawing die and on the shape change of metal during drawing. The article provides a methodology for calculating the energy efficiency of the wire drawing process. It is established that an increase in mechanical properties can lead to a decrease in the unhomogeneity of deformation over its cross section. It has been determined that for the formation of mechanical properties and the retention of the ductility margin of the wire, the drawing sequence must be constructed with the maximum degrees of deformation that are maximum permissible under the condition of continuous drawing, the minimum angle of die, and ensuring a low coefficient of friction. It is necessary to be guided not only by the quality criterion of the wire, characterized by the level of mechanical properties, but also by the energy efficiency of the process, for constructing resource-saving drawing sequences. The calculation of the power spent on shaping and overcoming the friction forces in the deformation zone showed that the efficiency of the drawing process increases with an increase in an elementary degree of deformation, a decrease in the working angle of the die and the value of the friction coefficient. The analysis of a typical drawing sequence from the point of view of these principles revealed that the resource-saving effect is achieved when using monolithic dies with a working angle of 8°. In this case, the route should be consistent with the remaining parameters of the deformation zone (an elementary degree of deformation and a coefficient of friction provided by the quality of preparation of the surface of the workpiece and the applied process lubricant).