Cold Drawing Process –A Review
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Praveen Kumar, Dr. Geeta Agnihotri / International Journal of Engineering Research and Applications (IJERA) ISSN: 2248-9622 www.ijera.com Vol. 3, Issue 3, May-Jun 2013, pp.988-994 Cold Drawing Process –A Review * ** Praveen Kumar , Dr. Geeta Agnihotri *(M.Tech Scholar, Department of Mechanical Engineering, M.A.N.I.T.,Bhopal) ** (Professor, Department of Mechanical Engineering, M.A.N.I.T.,Bhopal) ABSTRACT II. COLD DRAWING PROCESS-AN Cold drawing is widely used metal OVERVIEW forming process with inherent advantages like The Cold drawing is one of the oldest closer dimensional tolerances, better surface metal forming operations and has major industrial finish and improved mechanical properties as significance. It is the process of reducing the cross- compared to hot forming processes. Due to the sectional area and/or the shape of a bar, rod, tube or ever increasing competition with the advent of wire by pulling through a die. This process allows globalization it has become highly important to excellent surface finishes and closely controlled keep on improving the process efficiency in terms dimensions to be obtained in long products that have of product quality and optimized use of constant cross sections. It is classified as under: resources. In view of this different models have Wire and Bar Drawing: Cross-section of a been proposed and validated using experimental bar, rod, or wire is reduced by pulling it results over a long period of time. The demands through a die opening (Fig. 1 a) .It is in the automobile sector, energy sector and similar to extrusion except work is pulled mining sector have led to several modifications in through the die in drawing. Both tensile the drawing process. In this paper, process and compressive stress deforms the metal details of cold drawing, major analytical, as it passes through the die opening. experimental and numerical studies reported in Tube Drawing: It is a metalworking literature have been reviewed. The review process to size tube by shrinking a large focuses on highlighting the developments diameter tube into a smaller one, by associated with the drawing technology that drawing the tube through a die (Fig. 1 b). It includes improvement in tool design, is so versatile that it is suitable for both modification in product geometry, process large and small scale production. optimization etc. with the use of Finite element The drawing process improvement has been an method to achieve the process related objectives. area of extensive research over a long period of time due to its commercial significance as it Keywords-Cold drawing, Finite element method, offers excellent surface finish and closer Process optimization, Product geometry, Tool dimensional control in the products. design. I. INTRODUCTION Good quality and high precision products can be produced by several metal forming methods such as extrusion, drawing, rolling etc. Metal forming is the large group of manufacturing processes in which plastic deformation is used to change the shape of metal workpieces [1].The factors that determine the choice of the forming or for that matter any other process are Fig.1 Types of Cold drawing (a) wire and bar maximum utilization of resources with high quality drawing and (b) Tube drawing output. Both extrusion and drawing are net shape metal forming processes which have high material Earlier different analytical methods like utilization and produces parts with superior Slab method, Upper bound method or slip line metallurgical and material properties. This paper is theory were used for material flow and behaviour a review on cold drawing process with a focus on analysis. In the recent years with the development in the developments associated with the drawing Numerical techniques and with the advancement in process that includes improvement in tool design, computers there is tremendous rise in the accuracy modification in product geometry, process and pace of the solutions and information obtained optimization etc. with the use of modern techniques in the researches. like Finite element method to achieve the process related objectives. In this context, Finite Element Method is one of the most popular methods employed to resolve the 988 | P a g e Praveen Kumar, Dr. Geeta Agnihotri / International Journal of Engineering Research and Applications (IJERA) ISSN: 2248-9622 www.ijera.com Vol. 3, Issue 3, May-Jun 2013, pp. metal forming problems.Kopp [2] presented a report traditional section drawing method. It dramatically that described ways for the shortening, increased the manufacturing productivity, improved flexibilization and optimization, as important tools. the product quality, and reduced the manufacturing Numbers of studies on the analysis of drawing time and cost. process carried out by researchers are discussed A newly developed plug featuring a tiny below under different criteria. boss club structure in the sizing zone was proposed by Xu et al. [12]. It was found that when the plug III. LUBRICATION AND COEFFICIENT OF with a tiny boss club structure is adopted, the FRICTION contact quality is better and the larger plastic strain Establishing friction conditions is crucial in exists on the inner surface of the tube, which is very bulk metal forming because of the usually high crucial in improving the surface finish of the formed contact pressure and the influence of friction on the part. The evaluation of effect of tools’ geometries on material flow, tool stresses and the forming force the maximum possible tube deformation was studied [3]. The friction minimization by forming processes by Bihamta et al. [13] on variable thickness tube is reflected in: tool life increase, stagnation time drawing process with a newly developed procedure. reduce, increase of the machining process Based on the optimum design developed by Béland productivity, less energy consumption, less et al. [14] through a finite element model, a new tool consumption of tools and less production costs [4]. was built which minimised the maximum stress In the context of the same, Chuiko et al. [5] level to draw tubes in one pass. described the development in new forms of production lubricants and methods of oxalate V. TOOL GEOMETRY MODIFICATION application over Stainless Steel Tube. Lubricity Modification in conventional tube criteria of fatty-based oils (palm, groundnut and geometry like development of the Rifled Tubes etc., shea butter oils), an important aspect of oil as per the application requirement has also been a selection, were qualitatively assessed by Obi and part of several researches. Rifled Tubes have high Oyinlola [6] for friction evaluation for processes heat-transfer efficiency and therefore are used for like wire drawing and extrusion through open dies. the furnace wall tube in the large power plant Neves et al. [7] carried out experimental tests with a boilers. Assurance of high dimensional accuracy in laboratory drawing bench with three different the rifle tubes was given by Yoshizawa et al. [15] lubricants and two different lubrication conditions in with the help of a manufacturing technique order to study their effect on drawing loads and developed through experiments. Bayoumi [16] gave residual stresses. Similarly Byon et al. [8] performed an analytical solution for the problem of cold Wire drawing test for four different coating drawing through flat idle rolls of regular polygonal materials and two different lubricants as the metal tubular sections from round tube. The forming reduction ratio increased from 10% to 30%.Results tool load in plastic shaping of a round tube into a showed that the behaviour of drawing force varies square tubular section was determined by Bayoumi with the lubricant-type at the initial stage of and Attia [17] both analytically and numerically by drawing. applying finite element simulation. Parshin [18] utilized the obtained equations in the standard finite- 1V. IMPROVEMENT IN TOOL DESIGN element program to analyse the variation in the The profile design of die and mandrel is the shape of the eight-beam star like tubes in the course most important factor related to forming energy and of multipass drawing.Xu et al. [12] developed an deformation behaviour of tubular material [9]. aluminium tube with rectangular cross-section with Gunasekera and Hoshino [10] described a new high dimensional accuracy and surface finish. High method for obtaining optimal die shape which quality micro copper tube with straight grooves produces minimal stress in the extrusion or the (MCTSG) with an outer diameter of 6 mm was drawing of non-axisymmetric sections from round obtained by Yong et al. [19].The influence of bar stock. In order to find the best geometry of die drawing parameters on the forming of micro straight and plug to reduce the drawing force. , Neves et al. grooves was investigated based on the forming [7] simulated the cold drawing of tubes with fixed mechanism. Bihamta et al. [20] modified the plug by FEM with the commercial software MSC classical tube drawing process. The sinking and Superform. Kim et al. [9] investigated the process fixed-mandrel tube drawing methods were mixed parameters related with tool configuration. As a together to produce tubes with variable thickness in result, the advanced mandrel shape, which can the axial direction. effectively transmit, without generating defect, drawing force to deforming tube, was designed. VI. EFFECT OF RESIDUAL STRESSES Wang and Argyropoulos [11] designed, modified Residual stress and its measurement is very and analyzed a plum-blossom-shape die for the important aspect of cold drawing process as it has a direct cold drawing of hexagon/square-section rods significant impact on the material performance in in order to replace a series of converging dies in the the field. Minimisation of the induced tensile 989 | P a g e Praveen Kumar, Dr. Geeta Agnihotri / International Journal of Engineering Research and Applications (IJERA) ISSN: 2248-9622 www.ijera.com Vol. 3, Issue 3, May-Jun 2013, pp.