Influence of the Die Bearing Length on the Hydrogen Embrittlement of Cold Drawn Wires

2013 ◽  
Vol 577-578 ◽  
pp. 553-556 ◽  
Author(s):  
Jesús Toribio ◽  
Miguel Lorenzo ◽  
L. Aguado ◽  
Diego Vergara ◽  
Viktor Kharin
Keyword(s):  
Hydrogen Embrittlement ◽  
Hydrogen Diffusion ◽  
Cold Drawing ◽  
Wire Drawing ◽  
Wire Radius ◽  
Drawing Process ◽  
Strain Fields ◽  
Characteristic Value ◽  
The Wire ◽  
Definition Of

Prestressing steels, obtained by cold drawing, are highly susceptible to hydrogen embrittlement (HE) phenomena. Stress and strain fields produced by cold drawing play an essential role in this process since they affect hydrogen diffusion. Therefore, variations of such fields due to changes in drawing conditions could modify life in-service of these structural components. In this work the effect on HE of a parameter of the wire drawing process, thebearing length, is analyzed by means of diverse numerical simulations by the finite element method (FEM). The results of this work allow the definition of acharacteristic valueof the die bearing length equal to the wire radius, and demonstrate that the effects of stress-strain fields produced by wire drawing on HE are reduced when the bearing length exceeds such a characteristic value, so that the optimum cold drawing process is that with a bearing length higher than the wire radius.

Deformation Law of Cold Drawing Process of High Strength Bridge Cable Steel

2021 ◽  
Vol 1035 ◽  
pp. 801-807
Author(s):  
Xiao Lei Yin ◽  
Jian Cheng ◽  
Gang Zhao
Keyword(s):  
Strain Path ◽  
High Strength ◽  
Cold Drawing ◽  
Wire Drawing ◽  
Radial Deformation ◽  
Steel Bridge ◽  
Drawing Process ◽  
Single Pass ◽  
Potential Relationship ◽  
The Wire

High-strength cable-steel bridge is the “lifeline” of steel structure bridges, which requires high comprehensive mechanical properties, and cold-drawing is the most important process to produce high-strength cable-steel bridge. Therefore, through the ABAQUS platform, a bridge wire drawing model was established, and the simulation analysis on the process of stress strain law and strain path trends for high-strength bridge steel wire from Φ 12.65 mm by seven cold-drawing to Φ 6.90 mm was conducted. The simulation results show that the wire drawing the heart of the main axial deformation, surface and sub-surface of the main axial and radial deformation occurred, with the increase in the number of drawing the road, the overall deformation of the wire was also more obvious non-uniformity. In the single-pass drawing process, the change in the potential relationship of each layer of material was small, and multiple inflection points appeared in the strain path diagram; the change in the seven-pass potential relationship was more drastic, which can basically be regarded as a simple superposition of multiple single-pass pulls.

scholarly journals Influence of a modified drawing process on the resulting residual stress state of cold drawn wire

2018 ◽  
Vol 190 ◽  
pp. 04004
Author(s):  
Markus Baumann ◽  
Alexander Graf ◽  
René Selbmann ◽  
Katrin Brömmelhoff ◽  
Verena Kräusel ◽  
...  
Keyword(s):  
Residual Stress ◽  
Residual Stresses ◽  
Wire Drawing ◽  
Industrial Applications ◽  
Drawing Process ◽  
Die Geometry ◽  
Residual Stress State ◽  
Drawing Die ◽  
Process Modification ◽  
The Wire

Torsion bars are used in automotive engineering as well as in other industrial applications. Such elements are produced by bending cold drawn wires. In conventional drawing processes tensile residual stresses occur near the surface of the wire. Small bending radii, which are required in limited assembly spaces, result in component failure due to reduced formability. Additional operations such as heat treatment or shot peening are necessary to influence the residual stress of the wire and to improve the dynamic stability of the torsion bar. The aim of the research is to reduce tensile residual stresses near the surface of the wire in order to eliminate process steps and to enhance formability. Therefore, a forming technology is developed by using a modified drawing die geometry on the basis of gradation extrusion. Finite element simulation is used to investigate the influences of element geometry, number of elements and process modification on the resulting residual stresses after wire drawing of a steel alloy. The results are evaluated and compared with the conventional wire drawing process. Furthermore, the requirements for the design of an experimental test device will be outlined as well as the measurement of the residual stresses by using X-ray diffraction.

scholarly journals Effect of Process Parameters in Copper-Wire Drawing

Metals ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 105 ◽  
Author(s):  
Gustavo Aristides Santana Martinez ◽  
Wei-Liang Qian ◽  
Leonardo Kyo Kabayama ◽  
Umberto Prisco
Keyword(s):  
Hydrodynamic Lubrication ◽  
Copper Wire ◽  
Wire Drawing ◽  
Drawing Process ◽  
Stress Distributions ◽  
Operational Parameters ◽  
Die Geometry ◽  
Drawing Speed ◽  
Industrial Productivity ◽  
The Wire

The efforts to increase the operating speed of the wire drawing process play a crucial role regarding the industrial productivity. The problem is closely related to various features such as heat generation, material plastic deformation, as well as the friction at the wire/die interface. For instance, the introduction of specific lubricants at the interface between the die and the wire may efficiently reduce the friction or in another context, induce a difference in friction among different regimes, as for the case of hydrodynamic lubrication. The present study systematically explores various aspects concerning the drawing process of an electrolytic tough pitch copper wire. To be specific, the drawing speed, drawing force, die temperature, lubricant temperature, and stress distributions are analysed by using experimental as well as numerical approaches. The obtained results demonstrate how the drawing stress and temperature are affected by the variation of the friction coefficient, die geometry, and drawing speed. It is argued that such a study might help in optimizing the operational parameters of the wire drawing process, which further leads to the improvement of the lubrication conditions and product quality while minimizing the energy consumption during the process.

Prediction of die wear in the wire-drawing process

1997 ◽  
Vol 65 (1-3) ◽  
pp. 11-17 ◽  
Author(s):  
T.H. Kim ◽  
B.M. Kim ◽  
J.C. Choi
Keyword(s):  
Wire Drawing ◽  
Drawing Process ◽  
Die Wear ◽  
The Wire

The High Speed Wire Drawing Process of Steel Wires under Fluid Frictions Conditions

2016 ◽  
Vol 716 ◽  
pp. 76-84
Author(s):  
Maciej Suliga
Keyword(s):  
High Speed ◽  
High Carbon Steel ◽  
Wire Drawing ◽  
Drawing Process ◽  
The Finite Element Method ◽  
Wire Surface ◽  
Steel Wires ◽  
Drawing Speed ◽  
The Wire ◽  
Multiparameter Analysis

The essential purpose of the work was to determine the phenomena that occur in multipass wire drawing process of high carbon steel wires with high speed in hydrodynamic dies and to assess their influence on moulding the wire properties after the drawing process. The multiparameter analysis of the issues has involved the theoretical dissection of the phenomena arising in high speed wire drawing process in hydrodynamic dies with the usage of the finite element method supported by the experimental multipass drawing process in industrial conditions. On the basis of numerical analysis the influence of drawing speed on wire temperature was estimated. For final wires the investigation of mechanical properties, topogrhaphy of wire surface, the amount of lubricant on the wire surface, the pressure of lubricant in hydrodynamic dies were determined.

The Superposition of Longitudinal Sonic Oscillations on the Wire Drawing Process

1968 ◽  
Vol 183 (1) ◽  
pp. 545-562 ◽  
Author(s):  
C. E. Winsper ◽  
D. H. Sansome
Keyword(s):  
Experimental Data ◽  
Torsional Oscillation ◽  
Longitudinal Mode ◽  
Wire Drawing ◽  
Drawing Process ◽  
Drawing Force ◽  
The Coefficient Of Friction ◽  
The Wire ◽  
Oscillatory Energy ◽  
Good Agreement

Part 1: Characteristics of complete wire drawing apparatus Part 1 describes the wire drawing machine, instrumentation and oscillatory apparatus designed to establish the effects of applying oscillatory energy to the wire drawing process. A theoretical consideration of the vibration of the equipment is included and compared with experimental data. Tests were performed on a 3000 lbf bull-block and the oscillatory energy was supplied in a longitudinal mode from a 3000 lbf electro-hydraulic oscillator. Equipment was designed to measure drawing force, drawing torque, amplitude of die and drum oscillation, and drawing speed. Frequencies of die oscillation in the range 0–125 Hz were studied with amplitudes up to 0.070 in peak to peak. A study of process parameters, such as natural frequency of the system, damping of the bull-block drive, torsional oscillation of the drum, and die assembly inertia, showed that the analysis was in good agreement with experimental data and that it can be used to predict the effect of oscillations on the forces and torques acting during oscillatory wire drawing. Part 2 presents experimental data obtained from mild steel, hard aluminium, stainless steel and hard copper. Results show that there is no reduction in the peak drawing force and negligible reduction in the coefficient of friction. The results also confirm that oscillatory drawing is a mechanical process of straining and unstraining the drawn wire, and that the reduction in mean force can be determined by a mechanism of force superposition.

Influence of Thermomechanical Processing on the Martensitic Transformation Temperatures of NiTi SMA Wire

2010 ◽  
Vol 643 ◽  
pp. 43-48 ◽  
Author(s):  
Leonardo Kyo Kabayama ◽  
Odair Doná Rigo ◽  
Jorge Otubo
Keyword(s):  
Martensitic Transformation ◽  
Thermomechanical Processing ◽  
Cold Drawing ◽  
Wire Drawing ◽  
Mechanical Processing ◽  
Drawing Process ◽  
Intermediate Annealing ◽  
Transformation Temperatures ◽  
Area Reduction ◽  
Niti Sma

Most of the applications of NiTi SMA are as a wire form. In this sense it is important to know the effects of thermo-mechanical processing such as reduction per pass and intermediate annealing on the wire drawing process. For this work they were produced wire by cold drawing using 15 % area reduction per pass with and without intermediate annealing. The starting ingot was produced by VIM process. The influence of thermo-mechanical processing will be related to the martensitic transformation temperatures.

Optimization of Die design to abolish surface defect on Telescopic Front Fork (TFF) Tube

2021 ◽  
Vol 01 ◽  
Author(s):  
Asit Kumar Choudhary ◽  
Braj Bihari Prasad
Keyword(s):  
Outer Surface ◽  
Transverse Crack ◽  
Axial Stress ◽  
Substantial Reduction ◽  
Cold Drawing ◽  
Wire Drawing ◽  
Die Design ◽  
Drawing Process ◽  
Die Geometry ◽  
Area Reduction

Background: The telescopic fork is mainly used for suspension purposes in the different devices to absorb the vibration and disturbances from the road or mechanical devices. Factors such as die angle, drawing velocity, lubrication, and area reduction per pass significantly affect the drawing loads and residual stresses formed in the drawn tube during the tube marking process. Objective: Instantaneous transverse crack was found on the pipe's outer surface during the drawing process in the current work, and the key challenges were to reduce the percentage of pipe rejection. Methodology: In this work, optimum drawing die designs were proposed by using the finite element method (FEM). A FEM solving tool called Abaqus has been used for simulating and solving the cold-rolled process. The FEM model of the cold drawing process is generated in Abaqus with the same boundary condition (Axial load and constrain) as using on the actual wire drawing machine. Result: There was a substantial reduction in the area; axial stress (Tensile) along the die side is 672 MPa which is 23 % lower than the current die axial stress value of 877 MPa. A 48 % plastic strain was found along the purposed die side, which was 17 % lower than the existing strain of 64%. Finally, reduced the area by changing the die geometry from ~52% to 35 to 40 %. Conclusion: It was possible to abolish transverse crack on the pipe's outer surface to reduce the area reduction (35 to 40 %) in the output tube and strain (17 %). As part of the optimization of the FEM work process, this work gives us encouraging results. Further research will be considered for future positions.

Experimental and numerical analysis of the deformation in mild steel wire during dieless drawing

2002 ◽  
Vol 216 (3) ◽  
pp. 167-178 ◽  
Author(s):  
P Tiernan ◽  
M T Hillery
Keyword(s):  
Mild Steel ◽  
Steel Wire ◽  
Wire Drawing ◽  
Fe Model ◽  
Drawing Process ◽  
Distribution Profile ◽  
Dieless Drawing ◽  
The Wire ◽  
Drawing Dies ◽  
Good Agreement

Dieless wire drawing is the process of causing a reduction in a wire diameter without the use of conventional wire drawing dies. The wire, axially loaded with a force, is heated to an elevated temperature to initiate plastic deformation. The mechanics of this novel drawing process and a theoretical analysis of the deformation are discussed in this paper. The results of an experimental drawing programme carried out with mild steel wire at temperatures between 400 and 900°C are also presented. Mathematical models were developed and used to describe and predict the process deformation and both the stress and temperature distribution profile along the workpiece. A machine was designed and manufactured to facilitate an experimental programme of dieless drawing. The machine permitted continuous drawing of wire, while the reduction ratio, drawing load and temperature were automatically controlled using a personal computer. A finite element (FE) model of the wire was developed, and the results obtained from the FE analysis show good agreement with those obtained from both the experimental work and the mathematical modelling. Results obtained confirm that a complicated interdependence of the process parameters exists during the dieless drawing process.

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