Xue Dao Shu

Bending Analysis and Measures of the Forming of Automobile Semi-Axle on Cross-Wedge Rolling with Multi-Wedge

When forming automobile semi-axle using Multi-wedges Cross-Wedge Rolling (MCWR), it is difficult to avoid the rolling bending phenomenon. Thus to improve the product quality for finding out the causes and preventing rolling bending is essential. In this paper, the finite element model(FEM) analysis software Deform-3D was used to analize the bending causes, and giving the corresponding measures from numerical simulation of the forming of multi-wedge automobile semi-axle using Cross-Wedge Rolling. Based on the corresponding simulation experiments, the results indicate that the seasures is feasible. The results of this study for rolling forming of automobile semi-axle can improve product quality and provide a theoretical basis.

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.

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.

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.

Influence Analysis of Block Wedge on Rolled-Piece End Quality in Cross Wedge Rolling

Rolled-piece end quality is one of key factors to decide material utilization ratio in cross wedge rolling (CWR). Good workpiece end quality can improve material utilization ratio effectively. In the paper, by adding the block wedge near the end of mould, it can block surface metal which flows faster in the axial direction and avoid the end concavity of rolled piece. The material loss will not be present and good end quality rolled piece will be produced. The results are significant for improving material utilization ratio and promoting applications of CWR.

The Research on the Microstructure Evolution Law of Cross Wedge Rolling Asymmetric Shaft-Parts Based on Parity Wedge

Microstructure evolution is an effective means to improve the mechanical properties of products, shaft parts formed by cross wedge rolling is not only the shape of the formed parts, but more importantly it improves the comprehensive mechanical properties of the products by deformation. Therefore, the paper sets up the coupled rigid-plastic finite element model with deformation-heat transfer-microstructure by using nonlinear finite element method, and this model is adopted to make simulation calculation for the forming techniques of asymmetric shaft parts of cross wedge rolling based on parity wedge, specifically analyzes the rule of dynamic recrystallization and grain size distribution in the asymmetric rolled parts. The results show that the grain in the wedging place of asymmetric shaft parts of cross wedge rolling based on parity wedge can be obviously refined, and the research results of this paper may provide theoretical foundation for further improving the quality and mechanical properties of asymmetric shafts parts of cross wedge rolling.

Study on Production Mechanism of End Concavity in Cross Wedge Rolling

End concavity controlled effectively is one of important factors to achieve no material loss end of workpiece in cross wedge rolling (CWR). In the paper, nonlinear finite element modeling(FEM) for the process of CWR is presented with the aid of DEFORM software. The production mechanism of concavity on the end of rolled-piece is analyzed by displacement method, grid method and axial strain method. The reason of concavity is obtained that the surface metal flows faster than the center and the metal deformation in axle is uneven. The study is significant to avoid end concavity and realize no material loss end for rolled-piece.

Research on Process Parameter Optimization of the High-Neck Flange Closed Rolling Based on the Orthogonal Experimental Design

This paper simulates the process of the high-neck flange closed rolling on DEFORM-3D and optimizes the rolling process parameter by analyzing the results based on the orthogonal experimental design. For the high-neck flange, the results show that the effects on ellipticity are in the order of the mandrel feed speed, the main roll rotational speed and initial blank temperature. The former two factors show the significance while the initial blank temperature does not show that.

Study on Influence of End Concavity of Rolled Piece by Billet Circular Arc Angle with CWR

In order to solve the stub bar defects and improve the material utilization, this paper proposes the method of using billet with circular arc shape on the end face to control the end concavity. It establishes the cross wedge rolling finite element model by DEFORM-3D software, and through the displacement method to analyze the flow law of metal of rolled piece on the end face, and obtains the influence law of end concavity with different circular arc angles by numerical simulation. Finally, it gets the result that the end concavity length decreases with the increase of the circular arc angle. In comparison with the original billet, when the angle is 90°, the end concavity of rolled piece reduces by 69.04%. The results provide a theoretical basis for saving material and achieving the cross wedge rolling production without the stub bar.

Influence Regularities of Axial Force of Cross Wedge Rolling Symmetric Shaft-Parts about Technical Parameters

Because of unbalanced axial force of cross wedge rolling asymmetric shaft-parts causing the rolling play and not stably, it is key factors to restrict application in asymmetric shaft-parts of cross wedge rolling. Axial force balance depends on technical parameters. So the influence regularities of axial force to technical parameters is researched in this paper by Ansys-Ls/Dyna finite element software. Finite element model is authenticated by experiment of rolling force, and the influence regularities of axial force of cross wedge rolling asymmetric shaft-parts is get. It will provide a theoretical basis for choosing reasonable parameters in mold design of cross wedge rolling asymmetric shaft-parts.