International Scientific Journals
of Scientific Technical Union of Mechanical Engineering "Industry 4.0"

In this article, a number of theoretical studies have been conducted on a new combined process of multicycle thermomechanical processing, including wire drawing and subsequent cooling in liquid nitrogen. When analyzing the deformation, it was found that the presence of intermediate heating to ambient temperature allows calculating the force according to the Krasilshchikov formula and the wellknown nomogram of the tensile strength of AISI-316 steel at 20°C with minimal errors. The lack of heating leads to the fact that the second and third drawing cycles take place at partially negative temperatures in the workpiece section. This leads to an increase in the difference in the force values obtained by calculation and during modeling. To be able to use the Krasilshchikov formula and the nomogram of the tensile strength of AISI-316 steel at 20°C, it is necessary to adjust the resulting force values by increasing by about 30% for a diameter of 6 mm and 20% for a diameter of 9 mm in the absence of heating of the workpiece and by 35% for a diameter of 6 mm and 25% for a diameter of 9 mm in in case of preheating the workpiece.

The paper studies the evolution of microstructure and mechanical properties of copper wire during a new combined deformation process. The essence of the technological process is deformation of wire in a rotating equal-channel step matrix and subsequent drawing. The matrix rotates around the wire axis and thereby creates stress due to equal-channel angular drawing and twisting in the matrix. The deformed copper wire was investigated by transmission electron microscopy and EBSD analysis, as well as tensile tests and microhardness determination. The deformation resulted in an ultrafine-grained gradient microstructure having a high component of high-angle grain
boundaries. The tensile strength of the deformed copper wire compared to the undeformed one increases more than twice from 302 to 635 MPa, and the yield strength increases from 196 to 306 MPa, an increase of 56%. The use of such hardened copper wire in construction will reduce the weight of the structure by reducing the diameter.

In this work it was studied the influence of low-carbon steel wire annealing at different temperatures from 500 to 750 °C that was obtained by cold drawing on its structure and properties. It was sown that bigger work-hardening during the drawing process leads to the decreasing of collective recrystallization starting temperature, which could resulting in obtaining less plastic properties than are appear after lower annealing temperatures with additional loss of strength. The found effects give valuable information for cases when it is desirable to obtain the minimal strength or the maximum plasticity of the wire.

This article describes the technology of the combined process “equal-channel angular pressing-drawing”. The analysis of the influence of this process on the structure and mechanical properties of aluminum, copper and steel wires is given. The results of the study showed that the proposed combined deformation method “equal-channel angular pressing-drawing” has a significant advantage over the existing technology for the production of high-strength wire. This deformation method due to the combination of two deformations: severe plastic deformation in a matrix with parallel channels and the process of deformation through a drawing die, allows to get a wire with an ultra-fine structure and a high level of mechanical properties, the required size and shape of the cross section in a small number of deformation cycles.

The article considers theuse of manufacturing schemes of thermomechanical processing for production of various machine parts. Schemes of machines for wire and the sized steel introduced on the industrial enterprises are given. Machineswere developed by research teamheaded by Professor Oleg .I. Shavrin at Kalashnikov Izhevsk State Technical University. Comparison of the reached parameters for the developed technologies with basis technologies of thermal processing (typical for the given details) was presented.