Wire & Cable Technology International - January/February 2008 - (Page 58)

Expediency of Roller Dies Application in Wire Drawing — Part 1 by: Dr. Vladimir Bitkov Institute of Engineering Science of Russian Academy of Sciences (Ural Branch) 34 Komsomolskaja St. GSP 207 620219 Ekaterinburg, Russia www.imach.uran.ru An explanation of the decrease of losses on external friction in a roller die as compared with a traditional die. could be used for prediction of drawing force occurring while using the given drawing method with an acceptable degree of accuracy. The exact mathematical solution has to include the standard drawing process it is enough to apply the model received from the classical theory of plasticity and to create a similar model for a roller die. Traditionally it is accepted components as seen in Equation 1: Wtot = Wred + Wadd + Wfr + Wel + Wbt Where Wtot Wred on the basic plastic deformations determined by the initial and heat and potential energy of the metal (distortion of a lattice, increase of the free surface). Wadd overcoming additional plastic shear deformations proceedtransforms to heat. Wfr heat from action of friction forces on contact surfaces in the Wel expended on overcoming elastic deformations. Wbt increase of the basic deformation there is also growth of adaxial direction depends on several factors including external friction. Consequently, it is impossible to differentiate drawTherefore, calculation practice traditionally applies equilib- Roller dies have started to be applied for round wire drawing rather recently. Many researchers have repeatedly said that power consumption while drawing in roller dies is much lower, and they have explained it by a decrease of drawing force necessary for reduction of round wire section. Therefore, while researching roller dies in the drawing process, the main broach force through the roller dies and comparison the result with the drawing force in the traditional drawing method. To best understand the distinction in required drawing force while using these two methods, it is possible to use an energy consumption model and the various components of energy consumption relative to this model (on homogeneous deformation, friction and additional losses). There needs to be a obtained during tests for compression and stretching of rolled wire and samples of wires selected while drawing after each pass. Metallographic research of a wire can provide an answer as a result of different deformation conditions of the above mentioned wire rolling and drawing processes. Dealing With Friction Between the Wire Surface and Die Round wire drawing is a process of plastic deformation in which the material of rolled wire having the circular section is drawn through a conical hole of the die by stretching force applied to the end of a wire at the output of the die. And though this standard drawing method has many advantages and a considerable friction between wire surface and an internal die surface. Many attempts have been made and are being made standard drawing method. They are connected to improvement of die material, form and polishing, use of the improved lubricants, hydrodynamical drawing, applying of ultrasonic But the most fundamental way of external friction reduction while drawing is to draw in roller dies where the channel for reduction of wire section is formed by two or more nondrive rotating rollers with calibers. During the standard and consequently the relative speed between the surface of the tool and wire will be as high as possible. In the roller die, this relative speed is very low, which results in a determined 1960s.1 of the given drawing method, there is no sign of expansion of its application area due to several circumstances. Until now there has been no perfect drawing theory that 58 Wire & Cable Technology International/January 2008 The Effects of Plastic Shear Deformation drawing force while traditional or conventional drawing with the beginning of the twentieth century by K.B Levis. After this early research, there was almost no further progress in theoretical understanding of the wire drawing process. Within http://www.imach.uran.ru

Table of Contents Feed for the Digital Edition of Wire & Cable Technology International - January/February 2008

Wire & Cable Technology International - January/February 2008 Editorial Wire & Cable Events Industry News Global Economy Drives Specialty Cable Demand Corporate News Change is Tough! Top Products of 2007 New Magnesium Hydroxides Enabling Low-Smoke Cable Compounds Straight From the Show - IWCS Conference™ A History of Long-Term Thinking Ensures a Pioneering Spirit Expediency of Roller Dies Application in Wire Drawing - Part 1 WireDrawing 101 Strain Rate Transforming Our Ideas Into Your Success Straight From The Show - Wire Southeast ASIA 2007 Capstans, Dancers, Accumulators Roundup Spotlight On Quality Control Pioneering Virtual Technology for Extrusion Electrically Heated Furnace Cuts Energy Costs/Reduces Carbon Footprint Machinery Accessories Materials Polymer Developments in the Cables Industry Wire & Connector Top Products of 2007 Just Load, Click and Print Superior Flame Resistance for Minimal Smoke, CO & Acid Gas High-Flex Round Cable Added to On-Line Design Tools Failed Bridge Cables Replaced With Smaller, Stronger Ones Advertisers Index Classified Advertising Internet Spotlight Editorial Index

Wire & Cable Technology International - January/February 2008

For optimal viewing of this digital publication, please enable JavaScript and then refresh the page. If you would like to try to load the digital publication without using Flash Player detection, please click here.