A. V. Chernyaev (Tula State University, Tula), V. N. Chudin (Moscow State University Ways of Communications, Moscow), D. M. Tesakov (JSC «KBP named after Academician A. G. Shipunov», Tula)
Anisotropic material damageability evaluation at drawing with warming
Dependencies for calculating the damageability of the workpiece material during drawing without thinning the wall are proposed. The workpiece material is transversally isotropic under viscoplastic deformation. The equations of damage kinetics are used. Calculation results are given
Keywords: anisotropy; viscoplasticity; stress rigidity; damageability of material.
A. A. Pasynkov (Tula State University, Tula)
Orthogonal isothermal extrusion of parts with side appendages
The article discusses the process of isothermal extrusion of products with processes. The calculation of the process pressure and damage to the material accumulated during the deformation is given. The calculation is based on the energy method. The deformation scheme was assumed axisymmetric, the workpiece material is viscoplastic. Expressions are obtained for evaluating the pressure and damageability of the material, the influence of the strain rate on their values is established.
Keywords: orthogonal extrusion; isothermal deformation; viscoplasticity; pressure; failure.
D. V. Emelyanov, I. Z. Sungatov (Naberezhnye Chelny Branch of Kazan National Research Technical University named after A. N. Tupolev, Naberezhnye Chelny)
Force-moment characteristics during the drilling process
Changes in the force-moment characteristics during the drilling process depending on the depth of the hole being machined are considered and determined. On the basis of theoretical and practical research, a method for designing twist drills is proposed, the rigidity of which varies along the length of the drill. The proposed method will allow more efficient machining of holes, reduce the amount of rejects due to tool breakdowns, and reduce the consumption of cutting tools, which is undoubtedly relevant in modern engineering production.
Keywords: cutting tool; twist drills; helical chip flutes; drilling moment.
A. V. Platonov, D. V. Pronin (Arzamas Polytechnic Institute, a branch of the Nizhny Novgorod State Technical
University named after R. E. Alekseev, Arzamas); A. M. Vakhromeev (STU-MADI, Moscow); I. A. Platonov (JSC «Arsamassky Priborostroitelny named after P. I. Plandina», Arzamas)
Investigation of the chemical composition of automobile wheels made of light alloys and their mechanical characteristics for compliance with the requirements of State Standart 30599–2017
The objectives of the article are to study the chemical composition of the most common automobile wheels made of light alloys and to compare the mechanical characteristics (tensile strength, elongation, Brinell hardness) of the identified alloys with the requirements of State Standart 30599–2017. The discrepancy between the requirements for the mechanical properties of alloys according to State Standarts 1583–93, 4784–97, 11069–2001 and the requirements for the mechanical properties of wheels State Standart 30599–2017 was revealed. The necessity of studying the temperature effect on the structure and mechanical properties of wheels made of light alloys is determined.
Keywords: chemical composition; spectral analysis method; light alloy wheels; silumin; ultimate tensile strength; elongation; Brinell hardness.
Yu. N. Loginov, Yu. V. Zamaraeva (The Ural Federal University named after the first President of Russia B. N. Yeltsin, Institute of Physics of Metals named after M. N. Mikheev Ural Branch of the Russian Academy of Sciences, Ekateriburg)
Reverse extrusion of the cylinder with the use of back pressure
The scheme of back extrusion from a cylindrical billet of a metal cup with the use of back pressure is analyzed. The back pressure is created by a sleeve placed in the container. The inner diameter of the sleeve is smaller than the diameter of the punch, so the sleeve is first subjected to mandreling during the process. In the future, it is moved by the pressed metal of the workpiece, preventing its movement and creating a counter-pressure. The dependence of the back pressure on the process parameters is obtained. On the example of cast magnesium, the distribution of strain rates, strain, and axial stresses is determined by the finite element method. The conclusion is made about the effectiveness of the analyzed deformation scheme.
Keywords: stamping; back extrusion; magnesium; finite element method; stress; strain.
V. P. Volkov (Institute of Engineering Science, Ural Branch of The Russian Academy of Sciences, Ekaterinburg); D. R. Salikhyanov (Institute of Engineering Science, Ural Branch of The Russian Academy of Sciences, Institute of New Materials and Technologies, The Ural Federal University named after the first President of Russia B. N. Yeltsin, Ekaterinburg)
On fracturing during deformation of a retaining ring blank from steel alloyed with nitrogen
One case of fracturing large non-magnetic retaining ring at the stage of strain hardening by internal pressure of liquid is described. The reasons were investigated and methods for preventing the fracturing of rings during cold deformation by internal pressure of liquid are proposed.
Keywords: cold deformation; fracture; corrosion-resistant austenitic chromium manganese steel; alloying with nitrogen; nitride phase.