UDK 621.778:620.172 Professional article/Strokovni članek ISSN 1580-2949 MTAEC9, 47(2)245(2013) TENSILE PROPERTIES OF COLD-DRAWN LOW-CARBON STEEL WIRES UNDER DIFFERENT PROCESS PARAMETERS NATEZNE LASTNOSTI HLADNO VLEČENE MALOOGLJIČNE JEKLENE ŽICE PRI RAZLIČNIH PARAMETRIH PROCESA Cem S. ^etinarslan1, Ali Guzey2 1Department of Mechanical Engineering, Faculty of Engineering and Architecture, Trakya University, 22180 Edirne, Turkey 2Arsay Wire Production Company-Kirklareli, Turkey cemc@trakya.edu.tr Prejem rokopisa — received: 2012-10-01; sprejem za objavo - accepted for publication: 2012-10-23 This study demonstrates the influence of drawing-process parameters such as reduction (deformation) ratio and drawing velocity on the tensile properties of various low-carbon cold-malleable steel wires. Standard tensile tests were realized on four types of wires - SAE1006, SAE1008, SAE1015 (Cq15) and SAE10B22 (20MnB4) - at various process parameters. This experimental study shows how two of the main process parameters, the deformation ratio and drawing velocity, clearly influence the tensile properties (yield stress, ultimate tensile strength, and elongation at rupture) of steel-wire materials. Keywords: wire drawing, tensile properties, deformation (reduction) ratio, drawing velocity Ta študija prikazuje vpliv procesnih parametrov pri vlečenju, kot sta odvzem (deformacija) in hitrost vlečenja, na natezne lastnosti različnih maloogljičnih mehkih jeklenih žic. Izvršen je bil standardni natezni preizkus na štirih vrstah žice SAE1006, SAE1008, SAE1015 (Cq15) in SAE10B22 (20MnB4) po različnih procesnih parametrih. Ta eksperimentalna študija je pokazala, kako dva glavna procesna parametra, stopnja deformacije in hitrost vlečenja, vplivata na natezne lastnosti (napetost tečenja, natezna trdnost in raztezek pri pretrgu) jeklene žice. Ključne besede: vlečenje žice, natezne lastnosti, stopnja deformacije (odvzem), hitrost vlečenja 1 INTRODUCTION Wire drawing is a metal-reducing process, in which a wire rod is pulled or drawn through a single die or a continuous series of dies, thereby reducing its diameter. Wire drawing is one of the most common plastic-deformation processes. A wire rod is pulled or drawn through a die or a series of dies, causing a reduction of its diameter. In general, drawing is known as a process performed at room temperature. Drawing of low-carbon-content steel wires is generally conducted at room temperature employing a number of passes or reductions through several dies. Sometimes it may be performed at elevated temperatures for large wires to reduce drawing forces. Generally, steel wire is made of plain-carbon steel grades. The steel-wire materials are semi-products suitable for cold-drawing processes. Although a steel wire can be produced from stainless steel and other alloyed steels, in industry it is mostly produced using plain-carbon steels. The steel containing up to 1 % C is usually used for steel-wire production; however, the largest part of steel-wire production constitutes low-carbon steels with less than 0.1 % C.1 Ferrous wires are used as semi products for electrical wiring, ropes (rope wires are usually made of pearlitic steel and have very high tensile properties), cables, struc- tural components, springs, nails, spokes, musical instruments, electrodes, paper clips, etc.2 Several studies on wire-drawing processes and some process parameters that affect the wire-drawing process have been performed. Toribio and Ovejero have investigated the effect of cumulative cold drawing on the pear-lite interlamellar spacing in eutectoid steel. Interlamellar spacing in fully pearlitic steels decreases progressively during the cold-drawing process and the diminishing rate is not constant throughout the manufacturing route.3 The effect of degree of deformations, ranging from 5 % to 30 % reductions, on the mechanical properties of cold-drawn, mild-steel rods was experimentally investigated by Alawode and Adeyemi.4 Languillaume et al. have presented the results of a study concerning the influence of heavy cold drawing and post-deformation annealings on the microstructure of such pearlitic steel wires.5 On the other hand, Vega et al. have studied the effect of the process variables such as the semi-die angle, the reduction in area and the friction coefficient on the drawing-force value. The results of this study indicate clearly that friction has a significant effect on the drawing force, which becomes lower due to a decrease in the area reduction.6 The influence of the main process parameters (the wire yield stress - S, the cross-sectional area reduction - Re and the die half angle - a) on the shape quality and area fraction of the round-to-hexagonal composite wire drawing were investigated by Norasetha-sopon.7 This study shows that Re and S strongly influence the shape quality, and S slightly influences the change in the area fraction of the core. The change in the area fraction of the core, which equals zero, was obtained with the value of a that increased with the increasing S. Re and S strongly influence the drawing stress. Within this order, Re and S directly, strongly and inversely influenced the optimal die half angle. The pass schedule of a wire-drawing process designed to prevent a delamination of a high-strength-steel cord wire was studied by Lee et al.8 From their findings it is clear that the applied drawing process reduced the diameter of the wire from 3.5 mm to 0.95 mm, and that it consisted of nine passes. On the other hand, another model for predicting the fatigue strength of two different eutec-toid-steel wires, one of them being zinc coated, used in ropeway applications, has been presented by Beretta and Boniardi.2 Within this method the fatigue process of wires has been described in terms of propagation of the surface defects caused by cold drawing. The aim of our research was to investigate the tensile properties of various low-carbon cold-malleable steel wires with respect to drawing velocity and deformation ratio. These parameters also have an influence on the final wire quality, the drawing force, the lubrication in the process, the mechanical properties and the die wear. 2 EXPERIMENTAL PROCEDURE 2.1 Preparation process Wire-rod (raw) materials were of four different types of low-carbon steel: SAE1006, SAE1008, SAE1015 (Cq15) and SAE10B22 (20MnB4). The steel chemical compositions are given in Table 1.9 First, the chemical compositions of the steels were measured using a SPECTROLAB M7 spectrometric test device. Then the surface-cleaning process including two stages, the mechanical and chemical cleaning, was performed. The first step, the mechanical surface cleaning, was applied to remove the scale layer from the wires and Table 1: Chemical compositions of wire-rod (raw) steels Tabela 1: Kemijska sestava jekla v palicah Steel Type %C %Si % Mn %P %S %Cu %Cr %Ni %Mo %Al %B SAE1006 0.06 0.2 0.35 0.04 0.05 0.30 0.15 0.3 0.03 — — SAE1008 0.08 0.30 0.55 0.03 0.05 0.35 0.3 0.25 0.03 0,02 — SAE1015 0.14 0.15 0.40 0.02 0.015 0.1 0.08 0.1 0.05 0.03 SAE10B22 0.21 0.15 1.00 0.015 0.015 0.1 0.08 0.1 0.05 0.02 0.002 Table 2: Series of dies for each steel type for the drawing process (reduction of 5.5 to 4.8, to 4.00 and to 3.01) Tabela 2: Serija orodij za vsako vrsto jekla pri vlečenju (odvzem 5,5 do 4,8, do 4,00 in do 3,01) Inlet dia. Outlet dia. Pass number 1 2 3 4 5 6 7 8 9 5.50 2.20 8 4.80 4.21 3.72 3.31 2.96 2.67 2.41 2.20 — 5.50 1.80 8 4.67 4.00 3.44 2.98 2.60 2.29 2.02 1.80 — 5.50 2.10 9 4.82 4.25 3.77 3.37 3.02 2.73 2.49 2.28 2.10 then the chemical purification was realized. The chemical cleaning consisted of causticization (for 25 min in a KMnO5 + NaOH solution at 70 °C), dipping into an acid bath (for 1 h in a HCl concentrated solution at room temperature), washing and rinsing, passivation with lime and, finally, drying (for 1h at 100 °C). 2.2 Wire-drawing process After these treatments the drawing process was performed. Figure 1 shows the outlet of a drawing die with a coil (end product) and a drawing die (matrix) with a soap box. A wire first passes through the soap box and then through the die (matrix). The reduction of the diameter of a metal wire is realized by pulling it through the die (Figure 2). The working region of a die is typically and made of W carbide. The die is cooled with a cooling hose (water) as shown in Figure 1. A series of dies is used to obtain the required diameter reduction of the wire. Table 2 shows a series of dies with the reductions of 5.5 to 2.2, to 1.8 and to 2.1 made in 8 or 9 passes, used to obtain the wire diameters of (4.80, 4.00 and 3.01) mm. The reduction ratio (R/%) was determined for each diameter decrease as to the equation: Figure 1: a) Outlets of a drawing die with a wire coil and b) a drawing die (matrix) with a soap box Slika 1: a) Sestav vlečne matrice z navijalcem žice, b) matrica za vlečenje s posodo za milo Figure 2: Drawing die (matrix) with a tip (pressure type) Slika 2: Orodje za vlečenje (matrica) s konico (tlačne vrste) 500 0.450 S -g 400 j: 350 ei = 300 o £ 250 200 Yield Strength ^^SAE1008 m SAE1015 ■-■-" SAE10B22 >...... ...... 1 2 3 Specimen Number - After Drawing (Before Deformation) Figure 4: Variation in the yield-strength values for a rod and coil steel wire at a constant velocity and reduction ratio (from 05.50 to 04.81) Slika 4: Spreminjanje meje plastičnosti palice in žice v kolobarju pri konstantni hitrosti in odvzemu (od 05,50 do 04,81) In a multipass drawing process, the temperature rise during each pass can affect the mechanical properties of the final product (such as its bending and torsion properties, and its tensile strength).8 A wire-drawing process was carried out with different drawing velocities and different total-reduction ratios of the deformation to determine how the tensile properties of various low-carbon wires were affected. The effect of drawing velocity and deformation ratio was investigated in some references. One of those focused on the influence of drawing speed on the properties of multiphase TRIP (transformation induced plasticity) steel wires10 and the other on the study of the effect of total-reduction ratio on wire breaks by Cu fine-wire drawing.11 In general, each pass ratio is between 1.68 and 1.09. fl-i = k ■ f (k = 1.68-1.09) (2) 2.3 Tensile test Experiments were carried out on a tensile-test machine at room temperature (Figures 3 and 4) and SAE1006, SAE1008, SAE1015 (Cq15) and SAE10B22 (20MnB4) coil wires (end products) were used as test steels. The wires were submitted to tensile tests to determine the yield stress, the ultimate tensile strength and the elongation at rupture. Wire cuts of 250 mm in length were used as the test specimens. The tensile strength was determined on a 3 t tensile tester with a ram (lower jaw) speed of 10 mm/min using various test parameters and three experiments were carried out and then averaged for each point in the diagrams. 3 RESULTS AND DISCUSSIONS 3.1 Test results at a constant drawing velocity (3.6 m/s) and a constant reduction ratio (from $5.50 to $4.81) Firstly, the wire-rod specimens were tested and then the coil (drawn) wires were tested at a constant drawing velocity and a constant reduction ratio from 05.50 to 04.81. Experimental findings on the yield strength, tensile strength and elongation at rupture were determined for wire rods (before drawing) and coil (drawn) wires and are given in Table 3. The yield-strength values of rod wires and coil wires were found as expected and, as shown in Figure 4, they increase in accordance with the increasing C content. The increase in the C content causes brittleness, making Figure 3: Tensile-test machine Slika 3: Stroj za natezne preizkuse Figure 5: Variation in the ultimate tensile-strength values for a rod and coil steel wire at a constant velocity and reduction ratio (from 05.50 to 04.81) Slika 5: Spreminjanje vrednosti natezne trdnosti palice in žice v kolobarju pri konstantni hitrosti in odvzemu (od 05,50 do 04,81) Table 3: Tensile properties of a rod and coil steel wire at a constant drawing velocity and a constant reduction ratio (from 05.50 to 04.81) Tabela 3: Natezne lastnosti palice in žice v kolobarju pri konstantni hitrosti vlečenja in konstantnem odvzemu (od 05,50 do 04,81) Dia., 0/mm Material type V m/s Yield Strength Rp0,2/MPa Ultimate Tensile Strength Rm/MPa Elongation at Rupture % Specimen No Wire rod (before drawing) Coil (after drawing) Wire rod (before drawing) Coil (after drawing) Wire rod (before drawing) Coil (after drawing) Wire rod (before drawing) Coil (after drawing) 1 05.50 04.81 SAE1006 3.6 257 357 357 477 41 29 2 05.50 04.81 SAE1006 3.6 261 359 361 481 44 30 3 05.50 04.81 SAE1006 3.6 259 360 363 484 43 31 1 05.50 04.81 SAE1008 3.6 293 388 413 535 39 32 2 05.50 04.81 SAE1008 3.6 297 388 421 540 38 28 3 05.50 04.81 SAE1008 3.6 301 390 422 542 40 29 1 05.50 04.81 SAE1015 3.6 316 410 441 561 41 28 2 05.50 04.81 SAE1015 3.6 311 411 437 558 40 28 3 05.50 04.81 SAE1015 3.6 324 407 444 564 41 32 1 05.50 04.81 SAE10B22 3.6 408 480 568 689 36 25 2 05.50 04.81 SAE10B22 3.6 405 467 555 675 37 26 3 05.50 04.81 SAE10B22 3.6 400 471 540 666 39 29 plastic deformation more difficult. The ultimate tensile-strength values of the rod materials and coils of the tested steels are also in line with the increasing C content (Figure 5). The variation in the elongation at rupture is shown in Figure 6. The values of the elongation at rupture for drawn wires decreased with the increasing plastic deformation for all the tested steels. The (20MnB4) steel shows a slight decrease in the elongation due to a higher C content. The wire specimens used for the tensile tests are shown in Figures 7 and 8. Figure 6: Variation in the elongation-at-rupture (%) values for a rod and coil steel wire at a constant velocity and reduction ratio (from 05.50 to 04.81) Slika 6: Spreminjanje raztezka pri pretrgu (%) za palico in žice v kolobarju pri konstrantni hitrosti in odvzemu (od 05,50 do 04,81) 3.2 Test results at a constant drawing velocity (3.6 m/s) and different reduction ratios (from $5.50 to $4.81, to $4.00 and to $3.01) The coil materials were tested at a constant drawing velocity (3.6 m/s) and different reduction ratios (from 05.50 to 04.81, 04.00 and 03.01). The reduction ratio was determined as depending on the constant inlet diameter (05.50) and different outlet diameters (04.81, 04.00 and 03.01). Experimental findings are given in Table 4. The yield strength, tensile strength and elongation at rupture were determined for the wire rods (before drawing) and for drawn wires after various reduction ratios. Figure 8: SAE10B22 (20MnB4) specimen Slika 8: Vzorec SAE10B22 (20MnB4) Table 4: Tensile properties of a rod and coil steel wire at a constant drawing velocity (3.6 m/s) and different reduction ratios (from 05.50 to 04.81, to 04.00 and to 03.01) Tabela 4: Natezne lastnosti palice in žice v kolobarju pri konstantni hitrosti vlečenja (3,6 m/s) in različnih odvzemih (od 05,50 do 04,81, do 04,00 in do 03,01) Dia., 0/mm Material type V m/s Yield Strength Rp0,2/MPa Tensile Strength Rm/MPa Elongation at Rupture % Specimen No Wire rod (before drawing) Coil (after drawing) Wire rod (before drawing) Coil (after drawing) Wire rod (before drawing) Coil (after drawing) Wire rod (before drawing) Coil (after drawing 1 05.50 04.81 SAE1006 3.6 357 477 36 2 05.50 04.00 SAE1006 3.6 258 505 359 605 43 24 3 05.50 03.01 SAE1006 3,6 623 725 12 1 05.50 04.81 SAE1008 3.6 388 535 34 2 05.50 04.00 SAE1008 3.6 294 536 407 643 42 22 3 05.50 03.01 SAE1008 3.6 664 774 11 1 05.50 04.81 SAE1015 3.6 410 561 33 2 05.50 04.00 SAE1015 3.6 316 558 438 676 40 18 3 05.50 03.01 SAE1015 3.6 684 808 8 1 05.50 04.81 SAE10B22 3.6 480 689 31 2 05.50 04.00 SAE10B22 3.6 406 649 571 811 38 15 3 05.50 03.01 SAE10B22 3.6 772 944 5 The yield-strength values for all the specimens increase with the increasing reduction ratio (Figure 9); and the ultimate tensile strength for all the specimens Figure 9: Variation in the yield-strength values for a rod and coil steel wire at a constant velocity and different reduction ratios (from 05.50 to 04.81, to 04.00 and to 03.01) Slika 9: Spreminjanje meje plastičnosti za palico in žico v kolobarju pri konstantni hitrosti in različnih odvzemih (od 05,50 do 04,81, do 04,00 in do 03,01) shows similar tendencies (Figure 10). Variations in the elongation at rupture are shown in Figure 11. In general, the values of the elongation at rupture for coil wires decrease as the reduction ratio increases. The decrement is a bit larger for the relatively high C-content steel specimens, SAE1015 (Cq15) and SAE10B22 (20MnB4), as the increase in the reduction ratio is more effective for the steels containing a higher C content with respect to the strain hardening. In addition, the Mn content is also a strength-increasing alloying element for the steel SAE10B22.12 3.3 Tensile-test results at a constant drawing velocity (3.6 m/s) and different reduction ratios - different inlet diameters and constant outlet diameters Firstly, the wire rods were tested. The tests for coil wires were realized at the constant drawing velocity (3.6 m/s) and different reduction ratios (from 05.50 to 04.81 Figure 10: Variation in the ultimate-tensile-strength values for a rod and coil steel wire at a constant velocity and different reduction ratios (from 05.50 to 04.81, to 04.00 and to 03.01) Slika 10: Spreminjanje naztezne trdnosti palice in žice v kolobarju pri konstantni hitrosti in različnih odvzemih (od 05,50 do 04,81, do 04,00 in do 03,01) Figure 11: Variation in the elongation-at-rupture (%) values for a rod and coil steel wire at a constant velocity and different reduction ratios (from 05.50 to 04.81, 04.00 and to 03.01) Slika 11: Spreminjanje raztezka pri pretrgu (%) palice in žice v kolobarju pri konstantni hitrosti in različnih odvzemih (od 05,50 do 04,81, do 04,00 in do 03,01) Table 5: Tensile properties of a rod and coil steel wire at a constant velocity (3.6 m/s) and different reduction ratios - different inlet diameters and a constant outlet diameter - (from 05.50 to 04.81 and from 06.50 to 04.81) Tabela 5: Natezne lastnosti palic in žice v kolobarju pri konstantni hitrosti (3,6 m/s) in različnih odvzemih - različen vstopni premer in enak izhodni premer - (od 05,50 do 04,81 in od 06,50 to 04,81) Dia., 0/mm Material type V m/s Yield Strength Rp0,2/MPa Tensile Strength Rm/MPa Elongation at Rupture % Specimen No Wire rod (before drawing) Coil (after drawing) Wire rod (before drawing) Coil (after drawing) Wire rod (before drawing) Coil (after drawing) Wire rod (before drawing) Coil (after drawing) 1 05.50 04.81 SAE1006 3.6 258 357 358 477 43 36 2 06.50 04.81 SAE1006 3.6 500 605 24 1 05.50 04.81 SAE1008 3.6 292 388 405 535 42 34 2 06.50 04.81 SAE1008 3.6 531 643 22 1 05.50 04.81 SAE1015 3.6 314 410 436 562 40 33 2 06.50 04.81 SAE1015 3.6 553 676 18 1 05.50 04.81 SAE10B22 3.6 406 480 567 689 38 31 2 06.50 04.81 SAE10B22 3.6 645 811 15 and from 06.50 to 04.81). These ratios were determined according to different inlet diameters and constant outlet diameters. The results are shown in Table 5 and Figures 12, 13 and 14. The yield strength, tensile strength and elongation at rupture were determined for the wire rods Figure 12: Variation in the yield-strength values for a rod and coil steel wire at a constant velocity (3.6 m/s) and different reduction ratios - different inlet diameters and constant outlet diameters (from 05.50 to 04.81 and from 06.50 to 04.81) Slika 12: Spreminjanje meje plastičnosti palice in žice v kolobarju pri konstantni hitrosti (3,6 m/s) in različnih odvzemih - različen vstopni premer in enak izstopni premer (od 05,50 do 04,81 in od 06,50 do 04,81) Figure 13: Variation in the ultimate-strength values for a rod and coil steel wire at a constant velocity (3.6 m/s) and different reduction ratios - different inlet diameters and constant outlet diameters (from 05.50 to 04.81 and from 06.50 to 04.81) Slika 13: Spreminjanje natezne trdnosti palice in žice v kolobarju pri konstantni hitrosti (3,6 m/s) in različnih odvzemih - različen vstopni premer in konstanten izstopni premer (od 05,50 do 04,81 in od 06,50 do 04,81) Figure 14: Variation in the elongation-at-rupture (%) values for a rod and coil steel wire at a constant velocity (3,6 m/s) and different reduction ratios - different inlet diameters and constant outlet diameters (from 05.50 to 04.81 and from 06.50 to 04.81) Slika 14: Spreminjanje raztezka pri pretrgu (%) palice in žice v kolobarju pri konstantni hitrosti (3,6 m/s) in različnih odvzemih (od 05,50 do 04,81 in od 06,50 do 04,81) (before drawing) and coil (drawn) wires with different ratios. The yield strength, ultimate tensile strength and elongation at rupture were affected by the reduction ratio for each material as shown in Section 3.2. As the approximate reduction ratios (45.7 % for the reduction of 06.5 to 04.81 and 47.1 % for the reduction of 05.50 to 04.00) were considered, it was understood that the variation in the inlet diameters was not significant. 3.4 Tensile-test results at a constant reduction ratio (from 05.50 to 04.81) and with different drawing velocities (3.6 m/s and 2.4 m/s) The coil-wire tests were realized at a constant reduction ratio from 05.50 to 04.81 and different drawing velocities (3.6 m/s and 2.4 m/s). The results are shown in Table 6 and Figures 15, 16 and 17. It is observed that the yield stress and the ultimate tensile strength of the specimens increase with the increasing drawing velocity for each type of the materials. A higher C content leads to a higher yield and ultimate tensile Table 6: Tensile properties of a coil steel wire at a constant reduction ratio and different drawing velocities (3.6 m/s and 2.4 m/s) Tabela 6: Natezne lastnosti žice iz kolobarja pri konstantnem odvzemu in različnih hitrostih vlečenja (3,6 m/s in 2,4 m/s) Dia., 0/mm Material type V m/s Yield Strength Rp0,2/MPa Tensile Strength Rm/MPa Elongation at Rupture, % Specimen No Wire rod (before drawing) Coil (after drawing) Coil (after drawing) Coil (after drawing) Coil (after drawing) 1 05.50 04.81 SAE1006 3.6 357 477 36 2 05.50 04.81 SAE1006 2.4 310 455 38 1 05.50 04.81 SAE1008 3.6 388 535 34 2 05.50 04.81 SAE1008 2.4 350 510 36 1 05.50 04.81 SAE1015 3.6 410 561 33 2 05.50 04.81 SAE1015 2.4 370 536 35 1 05.50 04.81 SAE10B22 3.6 480 689 31 2 05.50 04.81 SAE10B22 2.4 444 650 33 Yield Strength 250 J 2,4 3,6 Velocity (m/s) Figure 15: Variation in the yield-strength values for a coil steel wire at a constant reduction ratio (from 05.50 to 04.81) and with different drawing velocities (3.6 m/s and 2.4 m/s) Slika 15: Spreminjanje meje plastičnosti žice v kolobarju pri konstantnem odvzemu (od 05,50 do 04,81) in različnih hitrostih vlečenja (3,6 m/s in 2,4 m/s) Elongation at Rupture 2,4 3,6 Velocity (m/s) Figure 17: Variation in the elongation-at-rupture (%) values for a coil steel wire at a constant reduction ratio (from 05.50 to 04.81) and with different drawing velocities (3.6 m/s and 2.4 m/s) Slika 17: Spreminjanje raztezka pri pretrgu (%) žice iz kolobarja pri konstantnem odvzemu (od 05,50 do 04,81) in različnih hitrostih vlečenja (3,6 m/s in 2,4 m/s) Ultimate Tensile Strength 2.4 3,6 Velocity (m/s) Figure 16: Variation in the ultimate-tensile-strength values for a coil steel wire at a constant reduction ratio (from 05.50 to 04.81) and with different drawing velocities (3.6 m/s and 2.4 m/s) Slika 16: Spreminjanje natezne trdnosti žice iz kolobarja pri konstantnem odvzemu (od 05,50 do 04,81) in različnih hitrostih vlečenja (3,6 m/s in 2,4 m/s) strength and a higher drawing velocity. Drawing velocity slightly affects the elongation, which decreases as the drawing velocity increases. These values are quite similar for all the steels. 4 CONCLUSIONS The wire drawing of SAE1006, SAE1008, SAE1015 (Cq15) and SAE10B22 (20MnB4) low-carbon, malleable-steel wires was investigated and their tensile properties were determined experimentally. This study contributes to the knowledge of tensile properties and the behaviour of drawn low-carbon steel wires during the cold-drawing process. The effect of the process parameters (reduction ratio, drawing velocity) were studied and it was found that the processing parameters have a major influence on the tensile properties in all four types of the low-carbon drawn steel wire. The obtained results can be summarized as follows: • The experiments have shown that the yield strength and ultimate tensile strength increase, while the elongation at rupture decreases for all the steels when the reduction (deformation) ratio is increased. • The drawing velocity has a significant effect on the tensile properties (the yield and the ultimate tensile strength) of low-carbon steel wires. A high drawing velocity causes high strength properties. The values of elongation at rupture also decrease as the drawing velocity increases. • It was determined that the reduction ratio has a larger influence on the tensile properties of low-carbon steel wires than the drawing velocity. • Due to a high C content, the tensile-strength properties of the wires increased for all the reduction ratios. In addition, Mn was also one of the strongly influential elements and its effect was amplified by increasing the strain rate for the SAE10B22 steel.12,13 The increase in the C content enhances the work-hardening rate.14 The work-hardening ability of steel increases with an increase in the C content. Thus, the C content causes a significant variation in the tensile strength of drawn steel wires. Moreover, it is known that B enhances the tensile properties of low-carbon steels.15,16 • The strength of rod wires can be improved using the wire-drawing process according to the experimental findings in this investigation. Furthermore, the wire-drawing-process parameters, like the reduction ratio and drawing velocity, also have a significant effect on the tensile properties of steel wires. Acknowledgements The authors would like to thank Mr. Ugur UZ for his help with the experimental work and to the ARSAY WIRE PRODUCTION COMPANY, Kirklareli/Turkey and the YILMAR STEEL WIRE AND SPRING COMPANY, Bursa/Turkey for their technical support in the experimental processes. 5 REFERENCES 1 T. Altan, S. Oh, H. L. Gegel, Metal forming, ASM, New York, 1983 2S. Beretta, M. Boniardi, Fatigue strength and surface quality of eutectoid steel wires, Int. J. Fatigue, 21 (1999), 329-335 3 J. Toribio, E. Ovejero, Effect of cumulative cold drawing on the pear-lite interlamellar spacing in eutectoid, Scripta Mater, 39 (1998) 3, 323-328 4 A. J. Alawode, M. B. Adeyemi, Effects of degrees of deformation and stress-relief temperatures on the mechanical properties and residual stresses of cold drawn mild steel rods, J. Mater. Process. Tech., 160 (2005) 2, 112-118 5 J. Languillaume, G. Kapelski, B. Baudelet, Evolution of the tensile strength in heavily cold drawn and annealed pearlitic steel wires, Mater. Lett., 33 (1997), 241-245 6 G. Vega, A. Haddi, A. Imad, An investigation of process parameters effect on the copper-wire drawing, Mater. Design, 30 (2009), 3308-3312 7 S. Norasethasopon, Influence of process parameters on shape quality and area fraction in round-to-hexagonal composite wire drawing, J. Mater. Process. Tech., 203 (2008), 137-146 8 S. K. Lee, D. C. Ko, B. M. Kim, Pass schedule of wire drawing process to prevent delamination for high strength steel cord wire, Mater. Design, 30 (2009), 2919-2927 9 A. Guzey, The Investigation of manufacturing process of ferrous wires, MSc Thesis, Trakya University, Natural and Applied Science Institute, Edirne 2009 10 M. Suliga, Z. Muskalski, S. Wiewiorowska, The influence of drawing speed on properties of TRIP steel wires, J. Achieve. Mater. Manuf. Eng., 26 (2008) 2, 151-154 11 H. Cho, H. H. Jo, S. G. Lee, B. M. Kim, Y. J. Kim, Effect of reduction ratio, inclusion size and distance between inclusions on wire breaks in Cu fine wiredrawing, J. Mater. Process Tech., 130-131 (2002), 416-420 12 A. A. Gol'denberg, N. P. Sukhikh, T. M. Mineeva, Effect of manganese and nickel on the strength of steel under rigid loading conditions, Met. Sci. Heat Treat., 13 (1971) 6, 487-489 13 M. Itabashi, K. Kawata, Carbon content effect on high-strain-rate tensile properties for carbon steels, Int. J. Impact Eng., 24 (2000), 117-131 14R. Song, D. Ponge, D. Raabe, Improvement of the work hardening rate of ultrafine grained steels through second phase particles, Scripta Mater., 52 (2005), 1075-1080 15 M. I. Haq, N. Ikram, The effect of boron addition on the tensile properties of control-rolled and normalized C-Mn steels, J. Mater. Sci., 28 (1993) 22, 5981-5985 16 P. Hausild, J. Siegl, P. Malek, V. Si'ma, Effect of C, Ti, Zr and B alloying on fracture mechanisms in hot-rolled Fe-40 (at.%)Al, Intermetallics, 17 (2009), 680-687