Development of Manufacturing Process Using Cold Incremental Forming Technique for Micro-Alloyed Non-Heat-Treated Material

2006 ◽  
Vol 510-511 ◽  
pp. 254-257 ◽  
Author(s):  
Hyoung Wook Lee ◽  
Geun An Lee ◽  
Duk Jae Yoon ◽  
Seo Gou Choi ◽  
Nak Kyu Lee ◽  
...  

A micro-alloyed non-heat-treated material does not need post heat treatment processes such as quenching and tempering after the forming process in production stages. This material can be called a green material since it can reduce industrial costs and harmful pollutants generated from post heat treatments. In this paper, near-net-shape forming processes were studied in order to make an automotive part using a micro-alloyed material. The cold forging technique using a former was utilized for the main shaping, and the cold incremental forming technique using a cross wedge rolling machine was adopted for the enhancement of strength and the final shaping of the part. In order to get more adequate process, the cross wedge rolling process is compared to the swaging process for the micro-alloyed steel and general carbon steels through experiments.

2011 ◽  
Vol 381 ◽  
pp. 72-75
Author(s):  
Bin Li

This paper investigates the interfacial slip between the forming tool and workpiece in a relatively new metal forming process, cross-wedge rolling. Based on the finite elements method, three-dimensional mechanical model of cross wedge rolling process has been developed. Examples of numerical simulation for strain, stress distributions and rolling load components have been included. The main advantages of the finite element method are: the capability of obtaining detailed solutions of the mechanics in a deforming body, namely, stresses, shapes, strains or contact pressure distributions; and the computer codes, can be used for a large variety of problems by simply changing the input data.


2012 ◽  
Vol 201-202 ◽  
pp. 1066-1070
Author(s):  
Zhan Li ◽  
Xue Dao Shu ◽  
Wen Fei Peng ◽  
Bao Shou Sun

The analysising of strain is the key factors to understand the forming mechanism of cross wedge rolling asymmetric shaft. due to the extrusion of dies and other external force, its interior,interactions can cause the relative position between the various parts. In order to study the deformation of workpiece at different degrees, pulling in the finite element strain field analysis, the strain of the analysis at deformation process is also a necessary precondition for forming and stress distribution. In this papre,By using Deform3D platform, the forming process of the cross wedge rolling on parity wedge asymmetric shaft is simulated. It is also to be analyzed the distribution and variation of the amount of strain in the rolling process, it shows that a cross-sectional and longitudinal section about the deformation characteristics of the strain fields, the results can achieve production of cross wedge rolling and provide important theoretical foundation to promote further cross-wedge rolling.


2012 ◽  
Vol 271-272 ◽  
pp. 406-411 ◽  
Author(s):  
Wen Yu Ma ◽  
Bao Yu Wang ◽  
Jing Zhou ◽  
Qiao Yun Li

The aim of this paper is to determine whether the train axle cross wedge rolling(CWR) using square billet as blank is available or not. Based on numerical simulation software DEFORM-3D, we built the finite element model. And the whole forming process was simulated successfully. The stress and strain distributions of workpiece in the process were analyzed. The effect of forming angle, stretching angle and billet size on rolling force was investigated, then determined the proper process parameters. The differences between the round billet rolling and the square billet rolling were obtained by comparing the tangential, axial and radial forces during the rolling process. The studied results show the availability of using square billet as blank in train axle CWR and provide important realistic meaning and application value.


2010 ◽  
Vol 154-155 ◽  
pp. 1779-1782
Author(s):  
Gui Hua Liu ◽  
Zhi Jiang ◽  
Yi Bian ◽  
Guang Sheng Ren ◽  
Chun Guo Xu

Cross wedge rolling (CWR) technology, which is a new metal forming process to produce stepped shaft in forging industry, has developed rapidly in the last decades. Tool wear is a key factor to influence products’ quality during CWR process in practice. Basing on the analysis of characteristic of the tool wear, the similar outline dimension of the worn tool in service is obtained by blocking up the end of the tool. A series of experiments are completed to research the influence of the tool wear on the center defects of the workpiece, and the available method to repair the worn tools is brought forward.


Materials ◽  
2018 ◽  
Vol 11 (8) ◽  
pp. 1278 ◽  
Author(s):  
Sutao Han ◽  
Xuedao Shu ◽  
Chang Shu

Considering problems about concaves at the stepped shaft ends, this paper established the plastic flow kinetic theories about metal deforming during the cross-wedge rolling (CWR) process. By means of the DEFORM-3D finite element software and the point tracing method, the forming process of stepped shafts and the forming mechanism of concaves at shaft ends were studied. Based on the forming features of stepped shafts, rolling pieces were designed using variable cone angle billets. Single-factor tests were conducted to analyze the influence law of the shape parameters of billet with variable cone angle on end concaves, and rolling experiments were performed for verification. According to the results, during the rolling process of stepped shafts, concaves will come into being in stages, and the increasing tendency of its depth is due to the wave mode, the parameters of cone angle α, the first cone section length n. Furthermore, the total cone section length m has an increasingly weaker influence on the end concaves. Specifically, cone angle α has the most significant influence on the quality of shaft ends, which is about twice the influence of the total cone section length m. The concave depth will decrease at the beginning, and then increase with the increasing of the cone angle α and the first cone section length n, and it will decrease with the increasing of the total cone section length m. Finite element numerical analysis results are perfectly consistent with experimental results, with the error ratio being lower than 5%. The results provide a reliable theoretical basis for effectively disposing of end concave problems during CWR, rationally confirming the shape parameters of billets with a variable cone angle, improving the quality of stepped shaft ends, and realizing the near-net forming process of cross-wedge rolling without a stub bar.


2018 ◽  
Vol 190 ◽  
pp. 11006 ◽  
Author(s):  
Zbigniew Pater ◽  
Janusz Tomczak

Rail axles are large-size parts produced in large batches. Currently, these parts are produced by metal forming techniques such as rotary forging, open die forging with hydraulic presses and open die hammer forging (minimum ram weight: 3 Mg). Nevertheless, not only are the above methods far from being efficient, they also lack accuracy (open die forging). As a result, new techniques for producing rail axles are constantly developed. One of such alternative techniques is based on the use of cross wedge rolling (CWR), which is the subject of the present study. An innovative roll design for producing rail axles by CWR is proposed. The rolls are provided with three pairs of wedge tools that act simultaneously on the workpiece and form the part in one revolution of the rolls, i.e., during 20 s. The numerical modelling of a CWR process with the proposed roll design reveals that the solution can be used to produce railway axles with the desired geometry. This technique, however, requires relatively high loads and torques. To decrease the force parameters, the forming process was modified and ran in two operations. The first operation consists in forming the central step of the workpiece while the other one involves the formation of steps on the ends of the workpiece. The results of the new simulation show a significant decrease in the loads and torques, which is caused, among others, by reducing the nominal diameter of the rolls from 1600 mm to 1200 mm. The numerical findings can be used to design a rolling mill for producing rail axles.


2005 ◽  
Vol 475-479 ◽  
pp. 3235-3238 ◽  
Author(s):  
Seo Gou Choi ◽  
Duk Jae Yoon ◽  
Geun An Lee ◽  
Hee Woong Lee ◽  
Kyoung Hoan Na

In general micro alloy steel have the higher strength relative to conventional steels, which limits the utilization of conventional plastic forming processes. Incremental forming processes are more suitable for cold forming of such a high strength material. In particular, cold cross wedge rolling (CWR) can be a potential tool to fabricate axi-symmetric components with multi steps using high strength micro alloy steel. Obviously, optimization of die shape design is a crucial factor to apply cold cross wedge rolling to micro alloy steels. In this regards, a simulation-based process design using an elasto-plastic FEM has been carried out in order to obtain an optimum die shape for cold cross wedge rolling in this paper. Analysis results provided that the stretching angle and the shoulder angle at knifing and guiding zones were significant parameters for the stable forming process. It was demonstrated that proper stretching and shoulder angles reduced an excessive slip between a work piece and die in CWR process despite the condition of the low friction coefficient.


2013 ◽  
Vol 395-396 ◽  
pp. 342-347
Author(s):  
Bin Shen ◽  
Song He Zhu ◽  
Heng Hua Zhang

Based on a improved mathematic model of predicting austenite grain size of hot rolled Nb-Ti micro-alloyed steel, a module for calculating microstructure evolution in the steel during hot-forming process was developed. To evaluate the recrystallization behavior according to the proposed model during plate multi-pass hot rolling, the multi-pass hot compression and its FE analysis in couple with the newly determined model were conducted. It indicated that the present models were capable of simulating the multi-pass hot compression and the actual multi-pass rolling process. After simulating an actual rolling process in factory by using the above models, evolution laws of microstructure were analyzed. Simulation results of microstructure had a good agreement with the measured ones.


2021 ◽  
Vol 11 (5) ◽  
pp. 2142
Author(s):  
Trung-Kien Le ◽  
Tuan-Anh Bui

Motorbike shock absorbers made with a closed die employ a tube-forming process that is more sensitive than that of a solid billet, because the tube is usually too thin-walled to conserve material. During tube forming, defects such as folding and cracking occur due to unstable tube forming and abnormal material flow. It is therefore essential to understand the relationship between the appearance of defects and the number of forming steps to optimize technological parameters. Based on both finite element method (FEM) simulations and microstructural observations, we demonstrate the important role of the number and methodology of the forming steps on the material flow, defects, and metal fiber anisotropy of motorbike shock absorbers formed from a thin-walled tube. We find limits of the thickness and height ratios of the tube that must be held in order to avoid defects. Our study provides an important guide to workpiece and processing design that can improve the forming quality of products using tube forming.


Materials ◽  
2018 ◽  
Vol 11 (11) ◽  
pp. 2125 ◽  
Author(s):  
Janusz Tomczak ◽  
Zbigniew Pater ◽  
Tomasz Bulzak

This paper presents selected numerical and experimental results of a skew rolling process for producing balls using helical tools. The study investigates the effect of the billet’s initial temperature on the quality of produced balls and the rolling process itself. In addition, the effect of billet diameter on the quality of produced balls is investigated. Experimental tests were performed using a helical rolling mill available at the Lublin University of Technology. The experiments consisted of rolling 40 mm diameter balls with the use of two helical tools. To determine optimal rolling parameters ensuring the highest quality of produced balls, numerical modelling was performed using the finite element method in the Forge software. The numerical analysis involved the determination of metal flow kinematics, temperature and damage criterion distributions, as well as the measurement of variations in the force parameters. The results demonstrate that the highest quality balls are produced from billet preheated to approximately 1000 °C.


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