Increase Of Drawing Speed Research Articles

Influence of wet wire drawing speed on the brass-plated steel cord properties

Steel cords are a reinforcing phase of the rubber-steel-canvas composite, and their properties, including strength, depend on the quality of the wires. The novelty of the work is a multi-parameter analysis of the cord production process, which showed that there is a relationship between the rheological properties of the lubricating emulsion, the friction conditions and deformation of the brass coating, and the properties of the wires and their resistance to cracking when braiding into a steel cord. It was shown that the friction conditions depend on the wire temperature and the rheological properties of the emulsion. As the drawing speed increases, the emulsion viscosity improves. The grease reaches its optimum at a specific drawing speed depending on the type of emulsion and the type of wire. Further increases in drawing speed result in an increase in temperature at the material/tool interface. This leads to a decrease in the viscosity of the emulsion and the breakdown of the lubricant film in the contact zone. Inappropriate selection of wet drawing speed contributes to a decrease in plastic properties and a reduction in the number of twists and bends of the wire, which leads not only to wire breakage at the stage of cord braiding but also to its premature breaking during the tensile test.

Effect of bismuth on the mechanical properties and microstructure evolution of iron matrix during drawing: a molecular dynamics study

This paper investigates the effects of bismuth nanoparticles on the mechanical properties and microstructure evolution of single-crystal iron matrix materials during the drawing process using molecular dynamics methods, and also explores the effects of different drawing speeds and loading methods on the drawing process. The results show that the incorporation of bismuth nanoparticles has a significant effect on the axial drawing force, dislocation, shear strain and crystal evolution during the drawing process. When the bismuth nanoparticles started to deform under the action of drawing force, the atomic shear strain and crystal evolution were concentrated around them, which hindered the generation of dislocations and led to the reduction of their axial drawing force. In addition, the degree of atomic shear strain and crystal evolution increases with the increase of drawing speed, leading to work hardening of the material, and thus increasing the axial drawing force. Finally, when the loading mode is positioned at the rear end, shear strain becomes more concentrated around the bismuth nanoparticles, hindering dislocation generation and increasing the material’s hardness and axial drawing force. This study is important for understanding the mechanism of bismuth nanoparticles on the iron matrix of single-crystal during the drawing process.

Effect of drawing speed on the deformation characteristics, microstructure and properties of copper wire rod

Currently, copper-based wire has been extensively applied in the information industry and for signal transmission due to its excellent performance in practice. Drawing speed, as a key parameter of the drawing process, has a significant impact on the production and quality of the wire. In this study, both simulation and experiment are performed to explore the evolution of deformation and damage behavior of copper wire and its microstructural properties during the process of multi-pass continuous drawing, with the drawing speed set to the range from 60 to 300 m/min. This provides guidance on the production and process optimization of the wire. It is revealed in the study that the surface of the pure copper wire is deformed more significantly than the core region, and that there is a rise in the equivalent strain and damage occurring at different locations in the longitudinal section of the wire as the number of passes increases. With the drawing speed increasing, the strain and damage occurring in the core region are reduced, while the damage caused by severe deformation on the surface shows nonlinearity. When the drawing speed increases, there is a significant improvement in the strength of the dominant texture component <101> in the copper wire, and the grain size of the wire is significantly refined. In the meantime, there is an increase in the density of dislocation within the wire. The severity of distortion caused to the grain tends to decrease, and the grain boundary is gradually blurred. By increasing the drawing speed, the surface quality of the wire is improved. Apart from that, there is a slight increase in the tensile strength, DC resistance and electrical resistivity of the copper wire, despite a decline in the conductivity of the wire.

A study of the formability of stainless steel foils during micro deep drawing

Stainless steel foils are extensively used in the manufacture of micro-metallic products for their excellent corrosion resistance, high mechanical strength and superior ductility. In the present work, stainless steel foils with 50 μm thickness were annealed at temperatures ranging from 750 to 1150 °C for 5 min and then cupped at drawing speeds ranging from 0.1 to 2 mm/min. The formability of metal foils was systematically investigated and the quality of drawn cups via micro deep drawing (MDD) was discussed. The results show that the total elongation of metal foils appears a gradual increase when annealing temperature rises from 750 to 950 °C. With a further increase of annealing temperature from 950 to 1150 °C, both the ultimate tensile strength and the total elongation decline sharply, while the scatter of stress increases. The results of MDD tests show that wrinkling problem becomes increasingly significant on the drawn cups whilst thickness distribution on the drawn cup mouth become quite nonuniform with the increase of drawing speed from 0.1 to 2 mm/min. Overall, optimal annealing temperature and drawing speed are obtained with the purpose of manufacturing high quality micro circular cups.

Influence of dynamic inhomogeneity of the stress-strain state on the modes of wire drawing in a monolithic conical die

The study of the wire drawing speed influence in a monolithic conical die on the stressstrain state inhomogeneity and drawing modes was presented. It was shown that the nonuniformity of stresses and strains during drawing in monolithic round dies could be divided into two types: static and dynamic. When drawing a round wire in a monolithic conical die, stress-strain state inhomogeneity occurs in the deformation zone, which results in microcracks at the wire center. The destruction degree depends on the value of &Delta;-factor, which characterizes the shape of the deformation zone. When the drawing speed increases, an additional speed or dynamic deformation inhomogeneity arises in the deformation zone due to the resulting acceleration and an increase in stresses. This causes a significant increase in the parameter &Delta; and the working half-angle of die, called &ldquo;dynamic&rdquo;. Analytical expressions were obtained for calculating the &ldquo;dynamic&rdquo; die angle and its velocity part. The analytical expressions analysis was carried out, the relationships between parameter &Delta; and the die half-angle on the drawing speed were obtained. A graphical dependence of the change in the safe zone, which excludes the destruction of the wire, on the value of the &ldquo;dynamic&rdquo; die angle and the degree of single deformation at various drawing speeds was plotted. It was shown that the &ldquo;safe&rdquo; zone decreases in proportion to the increase in the drawing speed. Solutions were proposed that provide an &ldquo;acceptable&rdquo; value of the parameter &Delta; for high-speed drawing. For this necessary to design wire drawing schedules using the maximum possible reductions per pass, and the values of the working half-angles of the wire drawing die, providing &ldquo;static&rdquo; inhomogeneity, should be reduced by the value of half-angles dynamic change. Wire drawing should be carried out at minimum tensile stresses.

Effect of die pressure on the lubricating regimes achieved in wire drawing

An experimental campaign of wire drawing was carried out under different conditions of average die pressure. Experiments were carried out measuring the drawing force and the temperature at the exit of the deformation zone with the use of a thermocouple closely located to the wire-die interface. Dies of three different semi-angles (6°, 7° and 9°), were employed to obtain different values of die pressure, while different lubrication regimes were achieved varying the drawing speed in the range 1–22 m/s. It was demonstrated that lubricating regimes of lower friction coefficient are achieved at smaller values of the drawing speed with increasing the die pressure. Likewise, the hydrodynamic regime arises at lower drawing speeds by increasing the die semi-angle. For example, it was observed that the hydrodynamic regimes developed at 19 m/s for the 6° die but at 15 m/s for the 9° die. This behaviour was correlated to the response of the lubricant viscosity to the die pressure by means of the Hersey analysis. The consequences of this finding on the problem of optimizing the die angle with the objective to reduce the drawing stress are discussed. On this basis, it is shown that the optimum die angle decreases as the drawing speed increases, other things being equal.

Laminated structure optimization and drawing performance of Al2O3–TiC/Al2O3–TiC–CaF2 self-lubricating laminated ceramic conical die

In the present study, Al2O3–TiC/Al2O3–TiC–CaF2 self-lubricating laminated ceramic conical dies were fabricated. Experiments were carried out to obtain values of hardness and fracture toughness of the conical dies for different laminated numbers and laminated thickness ratios. Drawing experiments were also conducted by a universal tensile testing machine. The worn surfaces were observed by a Scanning Electron Microscope (SEM) and Energy Dispersion Spectrum (EDS) to analyze the wear mechanisms and self-lubricating effect. Results show that the Al2O3–TiC/Al2O3–TiC–CaF2 self-lubricating laminated ceramic conical dies possess compact structure and well-bonding interface between layers. When the laminated number is 5 and laminated thickness ratio is 1:1, Al2O3–TiC/Al2O3–TiC–CaF2 self-lubricating laminated ceramic conical die reveals the best mechanical properties with the Vickers hardness and fracture toughness of 18.3±0.3GPa and 5.7±0.2MPam1/2 respectively. In addition, the drawing force decreases with an increase of drawing speed and drawing displacement under no lubrication condition. The wear mechanisms of Al2O3–TiC–CaF2 composites layer and Al2O3–TiC composites layer are mainly abrasive wear and adhesive wear. The conical dies׳ self-lubricating capacity has been generated by the ‘dragging effect’ during drawing process.

Analysis of the Heating of Steel Wires During High Speed Multipass Drawing Process/ Analiza Nagrzewania Się Drutów Stalowych W Procesie Ciągnienia Wielostopniowego Z Dużymi Prędkosciami

Abstract The analysis of the heating of the wire including theoretical studies showed that in the multistage drawing process a increase drawing speed causes intense heating of a thin surface layer of the wire to a temperature exceeding 1100°C, which should be explained by the accumulation of heat due to friction at the interface between wire and die. It has been shown that with increasing of drawing speed the heated surface layer thickness measured at the exit of the wire from the dies is reduced significantly and at drawing speed of 25 m/s is equal to about 68 μm. The decrease in the thickness of this layer can be explained by a shorter time of heat transfer to the wire, which causes additional heat accumulation in the surface layer. Thus fivefold increase in drawing speed caused an approximately 110% increase in the temperature in the surface layer of the wire. Experimental studies have shown that the increase of drawing speed of 5 to 25 m/s will increase the temperature of the wire after coiled on the spool more than 400%.

The Analysis of the Mechanical Properties of High Carbon Steel Wires after Multipass High Speed Drawning Process in Conventional and Hydrodynamic Dies

Abstract In this work the influence of the drawing speed on lubrication conditions and mechanical properties of high carbon steel wires drawn in conventional and hydrodynamic dies has been assessed. The drawing process of ϕ5.5 mm wires to the final wire of ϕ1.7 mm was conducted in 12 passes, in industrial conditions, by means of a modern Koch multi-die drawing machine. The drawing speeds in the last passes were: 5, 10, 15, 20 and 25 m/s. For final wires ϕ1.7 mm the investigation of mechanical properties has been carried out, in which yield strength, tensile strength, uniform and total elongation and also number of twists were determined. It has been shown that the increase of drawing speed from 5 m/s up to 25 m/s caused the increase by 6% strength properties and decrease of plasticity properties by 10%. Higher values of tensile strength and yield strength of the wires drawn conventionally with high speeds are associated with worse conditions, while in case of wires drawn hydrodynamically the main factor which caused the increase of strength properties was high lubricant pressure in hydrodynamic die, which caused the increase of total draft.

Investigation on Tribological Behavior of Advanced High Strength Steels: Influence of Hot Stamping Process Parameters

In order to investigate the friction and wear behavior of high strength steel in hot stamping process, a hot strip drawing tribo-simulator is developed and the friction coefficient, which is an important parameter in the finite element modeling, is measured. The results have shown that the friction coefficient remains almost unchanged until temperature reaches 500 °C. It then increases sharply as temperature is increased from 500 to 600 °C. It has also been shown that the friction coefficient decreases as the drawing speed increases. The change in the dominate wear mechanism as the temperature and the drawing speed increases has been identified from SEM analyses of the worn surface. The dominate wear mechanism is the groove cutting at temperatures between room temperature and 500 °C, which changes to the adhesive wear at temperatures above 500 °C. The main wear mechanism is the adhesive wear at 25 mm/s, which changes to the slight groove cutting at 75 mm/s.

The influence of die geometry on stress distribution by experimental and FEM simulation on electrolytic copper wiredrawing

The study of die geometry is vital in determining the surface and mechanical properties of drawn wires, and consequently, their application. In this work, annealed electrolytic copper wire (ETP), with 0.5 mm original diameter was reduced by 19% in dies with 2β = 10º and 18º and Hc = 35 and 50%. The best experimental results were then studied by the Finite Element Method to simulate residual stress distribution. The experimental results show that the friction coefficient decreases as the wire drawing speed increases, and that low 2β and Hc values bring about the most favorable wiredrawing conditions. The simulation shows a variation in the axial and radial tensions, both for the compression and traction stresses on all regions during the wire drawing process. In conclusion, the influence of the internal die geometry on the drawn wire is clarified.

Numerical simulation of solidification morphologies of pure copper by vacuum continuous casting using cellular automaton model and its experimental verification

The purpose of this study was to predict the morphologies of the solidification process for pure copper using vacuum continuous casting (VCC) and to verify its accuracy by comparing these findings with observed experimental results. A finite differential method and a cellular automaton (CA) model were used to simulate the macro-temperature field for nucleation and grain growth of pure copper using real data from actual casting operations. From the observed experimental results, the drawing speed of the VCC process was considered as the fundamental parameter. With the increase of drawing speed, morphologies of the copper changed and the position of the liquid–solid zone moved closer to the orifice of the mould. The solidification morphologies simulated with the CA model were in good agreement with the results from the actual casting experiment.

Study on the Mechanism about the Effect of Technological Parameters on Performance of Fiber Coupler

To find out the effect mechanism of technological parameters on the performance of fiber coupler, the relationship between the technological parameters and the optical performance is investigated by using a six-axes optical fiber coupler machine as experimental setup. It is discovered that the technological parameters such as drawing speed and fused temperature have a great effect on optical performance of fibre coupler. The fused region and taper region of fiber coupler are tested with scanning electron microscope (SEM). It is discovered that there are crystalline grains in the fused region. And the crystalline grains decrease while drawing speed increase. In the taper region, there are micro cracks. And the cracks are more obvious while drawing speed increases. When the fused temperature is above some point (here is 1350), the micro cracks in the taper region disappear and the optical performance of fiber coupler is the highest at this time.

The relationship between IR characteristic peak and microstructure of the glass used as optical fiber

Based on the harmonic vibration equation, the relationship between IR characteristic peak of fiberglass and Si-O-Si bond angle was deduced, and 1 100 cm−1 characteristic peak was specifically studied. It is found that 1 100 cm−1 characteristic peak shifts to higher wave number when Si-O-Si bond angle increases. Taking fused biconical taper (FBT) coupler as an example, the microstructures of the fiber coupler manufactured at different drawing speeds were tested with micro infrared spectrum. According to the test results, it is found that the bond angle at the taper region is the largest, the one at the fused region is the second largest, and the one of bare fiber is the smallest. The characteristic peaks of fused—taper region shift to higher wave number when drawing speed increases.