Papers by Keyword: Metal Flow

Abstract: To improve the quality of shafts parts end in cross wedge rolling, this paper applied closed type of cross wedge rolling technology to form shaft parts. By using finite element software DEFORM-3D, simulation of forming process for closed type of cross wedge rolling was carried out. The distribution of the stress field and strain field during stretching stage is characterized as the metallic flowing of the rolling forming process. These results have great theoretical significance and engineering application value in the study of the generated mechanism of the end concavity for the closed type of cross wedge rolling and the improvement of the quality of rolled piece end.

Abstract: According to a company’s trapezoidal stainless steel sieve bar specification, 4-stands pass system and rolling program are proposed. To verify the pass system, 4-stands sieve bar three-dimensional finite element model is established and simulated by ANSYS/LS-DYNA. Parameters, such as metal flow law (metal longitudinal flow, metal lateral flow) and power parameters (stress, strain and rolling force), are obtained, and provide a reference for new product pass design optimization and improvement.

Abstract: Punch is a key component in Socket-Spanner extrusion and its shape influence the extrusion molding heavily. Using the FEA software DEFORM, the paper simulated the extrusion process of three kinds of upper and lower extrusion punch combinations which have different shape and studied the influences of the punch shape on metal flowing, Z direction punch load and equivalent stress. By contrasting the simulation data, the best punch shape was chosen. Our results could provide theory evidence for optimization design of Socket-Spanner extrusion punch. It was shown that the tapered bottom punch is the most suitable shape for the socket-spanner extrusion than the flat tapered and the flat one.

Abstract: According to the production data of a rolling H-beam factory, the FE model of hot continuous rolling process of H-beam is built. With the FEM software of DEFORM-3D, the continuous rolling of H-beam was simulated. On base of simulation result, the metal flow and deformation law are discussed. Because of the flange and web is deformed in the different deformation zone, the metal flow law of flange and web is complex, especially the metal of the conjunction of flange and web. In this paper, the metal flow of large-sized H-beam in finishing rolling process is analyzed.

Abstract: Analysis of the basic characteristic of cross wedge rolling forming process and the stress -strain research at various stages are summed up in order to obtain the basic rule of law and the metal flow regular during forming.

Abstract: This paper is a synthetic presentation of the current state of knowledge on the fundamentals of cold production of thin and narrow steel strips. Such strips are semi-finished products used to manufacture final products which are widely used in a number of industries. The production devices are characterised and methods as well as technologies of their manufacture are discussed. For cases where wire is flattened to obtain strips with naturally rounded edges, the deformation phases with a uniform and non-uniform draft across the width of the strip have been identified. Changes in the widening coefficient and the rounding radius of the strip edge are described for these phases as a function of draft.

Abstract: When rolling thread shaft in cross wedge rolling, forming quality of thread is affected by many process parameters such as the thread helix angle, which is a special and complex parameter. However, there is few study of the effect of the thread helix angle on thread shaft forming. In this paper how thread helix angle affects axial metal flow was analyzed from the perspective of rolling force and the forming process of thread shaft was simulated with different helix angles by the deform-3D software. Through the measurement of the point coordinates, the effect of the helix angle on the axial metal flow of rolled pieces was analyzed. Finally, the conclusion was obtained that helix angle causes the asymmetry of axial metal flow with small difference values for asymmetry and the axial metal flow of rolled pieces increases as the helix angle increases. The rolling thread segment can be ensured in the middle of rolled pieces by moving the blank a suitable distance in the reverse direction of the axial flow direction.

Abstract: This paper presents the importance of simulation of metal flow in deep drawing process which employs an antilock brake mechanic system. Controlling the force and friction of the blank holder is imperative to assure that the sheet metal is not locked on the blank holder, and hence it flows smoothly into the die. The simulation was developed based on the material displacement, deformation and deep drawing force on flange in the radial direction, that it is controlled by blank holder with antilock brake mechanic system. The force to blank holder was applied periodically and the magnitude of force was kept constant during simulation process. In this study, the mechanical properties of the material were choses such that they equivalent to those of low carbon steel with its thickness of 0.2 mm. The diameter and the depth of the cylindrical cup-shaped product were 40 mm and 10 mm, respectively. The simulation results showed that the application of antilock brake mechanic system improves the ability to control the material flow during the drawing process, although the maximum blank holder force of 13000 N was applied. The optimum condition was found when the drawing process was performed using blank holder force of 3500 N, deep drawing force of 7000 N, friction coefficient of 0.25 and speed of punch stroke of 0.84 mm/sec. This research demonstrated that an antilock brake mechanic system can be implemented effectively to prevent cracking in deep drawing process.

Abstract: Aiming at the triple splitting rolling process of Φ14 mm ribbed bar in small section continuous rolling line, a nonlinear thermal-mechanical coupled finite element model was setup to investigate the splitting mechanism based on the normalized Cockroft-Latham criterion and algorithm of removing elements. From the simulation results, the exit cross section profile, stress and strain distribution of workpiece in each pass is presented. The metal separating in splitting pass and the cause of formation of the insufficient defect was discussed, and the prediction result is in good agreement with that of the practice in the steel company.

Abstract: To estimate the effect of roller deformation on the workpiece during the rolling process of H-beams, it is essential to consider the force exerted on the rollers and the deformation thereof. For this purpose, a three-dimension thermo-mechanical coupling model has been built with the finite element analytical package ABAQUS to simulate the hot rolling process of H-beams. In particular, the simulation is conducted under the assumption that the rollers are elastic and rolling torque imposed unilaterally, which agrees with the practical rolling conditions. Noting the results of FEM simulation, the metal flow and temperature distribution have been obtained. To verify the effectiveness of the proposed simulation, comparisons of the roller contact reaction and temperature between the simulated and measured values have been made. The simulation is meaningful for preparing continuous rolling procedures of H-beams.