Multi-wedge Cross Wedge Rolling Research Articles

Finite element analysis and experiment on multi-wedge cross wedge rolling for asymmetric stepped shaft of C45

A rigid-plastic finite element method (FEM) simulation model for a multi-wedge cross wedge rolling (MCWR) was developed to analyze an asymmetric stepped shaft. To evaluate the MCWR process and better understand its deformation characteristics, the material flowing mechanisms, temperature distributions, strain and rolling force were analyzed. The correctness of the finite element simulation is experimentally verified. Numerical simulations and experiments led to the following conclusions: when α=36° and β=7.5°, the quality of the work piece can be significantly improved. Finally, the development of the asymmetric stepped shaft is applied to industrial production.

Multi-wedge Cross Wedge Rolling Process of 42CrMo4 Large and Long Hollow Shaft

Abstract Large and long thick-walled hollow shafts are the key parts of industry equipments, which are formed by the multi-wedge cross wedge rolling (MCWR). In the present paper, first, the deflection angle equations of side-wedges applied at the multi-wedge cross wedge rolling of hollow shafts were derived, which lay important foundation for designing the MCWR mold. Second, the spreading angle's impacts on single-wedge cross wedge rolling (CWR) of thick-walled hollow shaft-part were discussed. And, compared to roll small diameter of hollow shaft, the ellipticity of the large and long thick-walled hollow shaft could be controlled, and the selection range could be extended. At the same time, it was also found that the ellipticity could also be controlled by empty top surface of the mold. At last, the FE model of double-wedge cross wedge rolling of large and long thick-walled hollow shaft was established. The forming process was simulated, and the ellipticity of symmetrical cross-section was monitored. The ellipticity of large and long thick-walled hollow shaft was controlled well. The simulated ellipticity of symmetrical cross-section is 4.98%, and the experimental ellipticity is 5.56%. The results indicate that it is feasible to produce large and long thick-walled hollow shafts with double-wedge CWR.

Analysis and experimental studies of internal voids in multi-wedge cross wedge rolling stepped shaft

In this study, a rigid-plastic finite element method (FEM) simulation model for a multi-wedge cross wedge rolling (MCWR) was developed to analyze the generation mechanisms of internal defects. Two feature parts in MCWR, rod area and store area, were defined to analyze the internal defects mechanisms. The difference of stress states between the rod and store areas was pointed out and an insight into generation mechanism was concluded. Based on simulation, the influence of mold parameters was discussed and an optimized parameter group was achieved. The results indicate that the internal voids in the store and rod areas were extended from microcracks produced by shear stress cycle, and then develop to cracks due to the overlarge first principle tension stress caused by metal backflow. In a certain range, a smaller forming angle and a reasonable area reduction is good for avoid center voids in store area. Subsequently, the industrial test manifested the feasibility of study results.

The Strain Analysis at the Broadening Stage of the Hollow Railway Axle by Multi-Wedge Cross Wedge Rolling

The paper is based on the newest hollow railway axle, which utilizes the Pro/E designed multi-wedge cross wedge rolling (MCWR) model, utilizes the finite element analysis software DEFORM-3D to complete the numerical simulation about the whole stage of the hollow railway axle forming process, and analyzes the strain rule at the broadening stage of the hollow railway axle, especially conducts a detailed research on forming character into the strain rule at the multi-wedge transition stage, and finally gets the strain forming mechanism of the hollow railway axle at the broadening stage. The result of the research on the strain rule poses great scientific significance on enhancing the product quality and the production efficiency of the hollow railway axle, and improving the theory of multi-wedge cross wedge rolling.

Research on the Status and Prospect of the Hollow Shafts Forming Technology in High-Speed Train

High-speed and heavy-load are the targets to pursue over a long period of time in high-speed transportation. The key to solve this problem is making the components lightweight. Particularly, the hollow shaft is a new type of lightweight construction. This article explains systematically the current situation and the defects of forming technique for the hollow shafts. The solid shafts formed by Multi-Wedge Cross Wedge Rolling (MCWR) and the hollow shafts by Cross Wedge Rolling(CWR) are researched, and the key problems of hollow shafts formed in MCWR to solve emphatically are pointed out. At the same time, we obtain that MCWR will be the main technology in forming long shafts. The results in this paper provide a new direction for the hollow shafts to form in a high efficiency, energy saving and material saving method.

Feasibility Study on Forming Hollow Axle with Multi-Wedge Synchrostep by Cross Wedge Rolling

One direction of the cross wedge rolling technology is to realize high-efficiency, precise and near-net-shape forming hollow axle with multi-wedge synchrostep cross wedge rolling. This paper deduced the rotated condition of forming hollow shaft with multi-wedge cross wedge rolling (MCWR) base on forming solid shaft with single-wedge cross wedge rolling, and analyzed technics parameters on the influence of rotated conditions. Through the finite element simulation we got rolling technics parameters on the effect of rolled piece and selecting principle, and then created the 3D model of the equal diameter period of hollow axle with the MCWR. By using DEFORM-3D software, the process of rolling equal diameter period was simulated. The result indicated that it is feasible to roll hollow axle with multi-wedge synchrostep by cross wedge rolling.

Theoretical Analysis of the Displacement on the End-Section of the Rolled Parts for Multi-Wedge Cross Wedge Rolling

Multi-wedge Cross Wedge Rolling (MCWR) is an advanced technology in forming long axial parts, and it does not have the disadvantages of Single-wedge Cross Wedge Rolling (SCWR).However, it is extremely important to realize the regularity of the displacement on the end-section of the rolled parts in MCWR due to the complexity of its forming mechanism. In this paper, based on the method of the displacement on the end-section of the rolled parts in SCWR, the rules of the displacement on the end-section of a typical rolled part in MCWR were investigated theoretically, and the curve on the end -section of the rolled part in MCWR were analyzed.Based on the curve, the regularity of metal flowing and the characteristic of forming for the typical rolled part in each phase by MCWR were analyzed. It is of high value in studying the forming mechanism and designing mould and technics in MCWR.

The Application of Multi-Wedge Cross Wedge Rolling Forming Long Shaft Technology

The process of multi-wedge cross wedge rolling is an advanced precision technology for forming long shaft parts such as automobile semi-axes. Three-dimensional solid model and the finite element model of semi-axes on automobile and dies of its cross wedge rolling were established. The process of cross wedge rolling was simulated according to the actual dimension of semi-axes on automobile utilizing the finite element method (FEM)software ANSYS/LS-DYNA. The required force parameters for designing semi-axes mill are determined. The appropriate roller width was determined according to the length and diameter of semi-axes on automobile. The results have provided the basis for the design of specific structure of automobile semi-axes cross wedge rolling mill.

Simulation of forming automotive semi-axes with multi-wedge cross wedge rolling

The surface quality of automotive semi-axes is influenced by side wedging shape directly in forming automotive semi-axes with multi-wedge cross wedge rolling (MCWR). In this paper, through choosing proper shape of side wedge, the three-dimensional finite element model was established which forming automotive semi-axes with MCWR. The automotive semi-axis with smooth transition surface is simulated successfully through choosing suitable technological parameters. The results indicated that the process of MCWR forming automotive semi-axes is feasible; moreover, this study provides the reliable theory foundation for design of MCWR dies rolling automotive axes.

The Influence Rules of Stress about Technical Parameters on Synchronous Rolling Railway Axis with Multi-Wedge Cross-Wedge Rolling

Multi-wedge synchronous rolling by cross-wedge rolling is one of the most advanced methods that can form rolling railway axis. Its rolling quality mainly lies on inner transversal stress and shearing stress of rolling workpiece. In this paper, based on the rotated theory of multi-wedge rolling, through using Ansys/Ls-Dyna FEM software, multi-wedge synchronous rolling railway axis by cross-wedge rolling is simulated. It has been systemically researched that technical parameters effect transversal stress and shearing stress. In the meantime, the calculating model is verified by experiment. Through this study, It is obtained that the law of technical parameters effect on rolling railway axis by multi-wedge synchronous cross-wedge rolling. These research conclusions can provide scientific basis for rolling railway axis by multi-wedge synchronous cross-wedge rolling and rolling better quality.

Investigation into Regularity of Movement of the End of Wedged Parts for Cross Wedge Rolling

Multi-wedge cross wedge rolling (MCWR) is one kind of plastic forming,including radial screwdown,axial extension and horizontal enlarging by both wedges at the same time.With the fast development of traffic and transport industry,the demand for long shaRs such as train shaRs and automobile semi-axes is daily on the increase.MCWR has many advantages in forming long shafts, such as saving roll surface remarkably,reducing equipment volume,high production efficiency,saving material and reducing cost.To give full play to the advantage of multi-wedge in significantly saving roll surface and to maintain wedging the work piece simultaneously by internal and external wedges,it is necessary to accurately ascertain the regularity of movement of the end of wedged parts.Elastic-plastic finite deformation finite element numerical method is used.The cross wedge rolling (CWR) process is simulated successfully according to actual operating conditions,the regularity of movement of wedged parts is analyzed and the regularity how movement is affected by technological parameters is elaborated.The regularity of movement of the end of wedged parts is discovered after the analog results are compared to the experimental results.The research results provide an important theoretical basis for the design of MCWR moulds and perfect the theory of MCWR.

Influence Rule of Technological Parameters on Interface Quality of Multi-wedge Cross Wedge Rolling Workpiece

Multi-wedge cross wedge rolling technique is an advanced method for forming a long shaft part,but in the production process the influences of technological parameters of dies on the interface quality of workpiece is complicated.A three-dimensional finite element model for forming a long shaft part with the multi-wedge cross wedge rolling technique is established on the basis of the characteristic of multi-wedge cross wedge rolling die.The process of multi-wedge cross wedge rolling forming a long part is simulated on different technological parameters by means of ANSYS/LS-DYNA FEM software,then the influence rule of technological parameters on interface quality of workpiece is obtained.The rolling test is carried out under the same technological parameters as that of simulation,the test results tally with the simulation results.It is concluded that in the technological parameters the transition angle has the most influence on the interface quality of workpiece while the stretching angle has the least.The rational scope of transition angle is worked out.The research results provide the theoretical basis and reference for the design of dies for multi-wedge cross wedge rolling forming of long shaft parts.

Computer aided design for cross wedge rolling tools of automobile semi-axes

Abstract The multi-wedge cross wedge rolling (MCWR) is a new advanced technology of forming automobile semi-axes with many advantages such as saving the surface of roller remarkably and reducing the size of equipment. The design and calculation of dies is complex, therefore, the technology of MCWR forming automobile semi-axes is limited in practical application to some extent. In order to solve the problems above, the Pro/Engineer was further developed using visualized basic program language, and the complex calculation program for the parameters was worked out including main wedges and side wedges, the movement of the end of rolled part in rolling and shaping curves in each phase on MCWR tools of automobile semi-axes, and then the calculated results were placed in access database and using the software of Pro/Engineer to module for the MCWR tools, which achieve the CAD parametric design for automobile semi-axes and provide an efficient method for the production of automobile semi-axes.