Determining and Optimizing of Guide Rolls Motion Track in Cold Ring Rolling Process

2006 ◽  
Vol 532-533 ◽  
pp. 141-144 ◽  
Author(s):  
Zhi Chao Sun ◽  
He Yang ◽  
Lan Yun Li

Guide rolls play an important role in controlling both the ring circularity and the stability of cold ring rolling process. However, it is difficult to predict and control the motion of the guide rolls due to the complexity of process associated with the coupled effects of multi-factors. In this paper, a reasonable controlling model of the guide rolls is proposed, and the functional relationship between the motion track of the guide rolls and their setup parameters and process ones is established, by which the guide rolls motion track can be determined. On this basis, a 3D-FE simulation model for cold ring rolling is developed under the ABAQUS software environment and the effects of the initial position and motion track of the guide rolls on the forming stability, ring circularity, rolling force, and oscillating are investigated. Taking the forming stability and ring circularity as objects, the optimum initial position and motion track of the guide rolls are obtained.

2007 ◽  
Vol 561-565 ◽  
pp. 1875-1878 ◽  
Author(s):  
Yong Xing Hao ◽  
Lin Hua ◽  
Gui Shan Chen ◽  
Dao Ming Wang

Non-stability factors affect stability of radial ring rolling process, and lead to fluctuating of ring position. This decreases rolling precision. Evaluating stability of the process is very important. A stability evaluating method is proposed. The stability can be measured with the mean square root of sequence of oscillation of ring geometrical centerline displacement. Using ABAQUS/Explicit, the stability is analyzed. It is showed that guide-roll position angle has the significant effect to the stability. If guide-roll is located at the tangential position to the ring’s fringe, the stability will vary with the angle between two planes. One passes through axes of guide roll and ring blank, and another passes through axes of drive roll and ring blank. The stability is highest when guide roll is situated at the position angle of 100˚to 130˚at exit side of ring rolling mill.


2011 ◽  
Vol 264-265 ◽  
pp. 235-240
Author(s):  
Nassir Anjami ◽  
Ali Basti

Ring rolling process, especially hot rolling is characterized by 3D deformation, continuous change of thickness and height, high nonlinearity, non-steady flow and asymmetry. It involves both mechanical and thermal behaviors. Most mechanical and physical properties and boundary conditions are temperature related. The heat flow and stress analysis cannot be analyzed separately. In this study, both isothermal and coupled thermo-mechanical (CTM) 3D rigid-plastic finite element (FE) models of the hot ring rolling (HRR) process are developed to investigate their differences in accurately and quickly predicting the process. The results show that the latter should be more advantageous to the more accurate prediction and control of microstructure and properties of the ring.


2011 ◽  
Vol 264-265 ◽  
pp. 1776-1781 ◽  
Author(s):  
Nassir Anjami ◽  
Ali Basti

Although cold ring rolling (CRR) process is largely used in the manufacturing of profiled rings like bearing races, research on this purpose has been scant. In this study, based on a validated finite element (FE) model, CRR process is simulated regarding the variable and constant feed speeds of the mandrel roll which lead to constant and variable values of the ring's diameter growth rates respectively using a 3D rigid-plastic finite element method (FEM). Major technological problems involved in the process including plastic deformation behavior, strain distribution and its uniformity, Cockcroft and Latham damage field and final outer diameter of ring are fully investigated. The results of simulations would provide a good basis for process control especially feed speed controlled mills and guiding the design and optimization of both cold and hot ring rolling process.


2013 ◽  
Vol 762 ◽  
pp. 354-359 ◽  
Author(s):  
Thomas Henke ◽  
Gerhard Hirt ◽  
Markus Bambach

Ring rolling is an incremental bulk forming process. Hence, the process consists of a large number of alternating deformations and dwell steps. For accurate calculations of material flow and thus ring geometry and rolling forces in hot ring rolling processes, it seems necessary to consider material softening due to static and post dynamic recrystallization which could occur between two deformation steps. In addition, due to the large number of cycles, the modeling results, especially the prediction of grain size, can easily be affected by uncertainties in the input data. However, for small rings and ring material with slow recrystallization kinetics, the interpass times can be short compared to the softening kinetics and the effect of softening can be so small, that microstructure evolution and the description of the materials flow behavior can be de-coupled. In this paper, a semi-empirical JMAK-based model for a stainless steel (1.4301/ X5CrNi18-9/ AISI304) is presented and evaluated by the use of experiments and other investigations published in [1],[2]. Finite Element (FE) simulations of a ring rolling process with a high number of ring revolutions and thus multiple, incremental forming steps were conducted based on ring rolling experiments. The FE simulation results were validated with the experimentally derived rolling force and evolution of ring diameter. The microstructure evolution was calculated in a post processing step considering the investigated evolution of strain and temperature. In this calculation the interrelations between the fraction of dynamically recrystallized microstructure, the evolution of post-dynamically recrystallized microstructure and the final grain size have been considered. Both, the calculated final microstructure and the evolution of rolling force and ring geometry calculated stand in good agreement with the experimental investigations.


2011 ◽  
Vol 383-390 ◽  
pp. 2819-2826
Author(s):  
Ali Parvizi ◽  
Karen Abrinia

A generalized upper bound solution for the deformation of ring in the ring rolling process has been formulated. An admissible velocity field and strain rates are derived from the parametric definition of streamlines in the deformation zone. This new formulation was used to predict the upper bound on power. Minimizing the upper bound power with respect to neutral point position, the neutral point position and the rolling force were determined. Using the theory presented here, the variation of internal, shear, frictional and total powers with respect to ring revolution are discussed. Some of the results obtained from analysis were compared with experimental results.


2002 ◽  
Vol 125-126 ◽  
pp. 613-618 ◽  
Author(s):  
Hiroshi Utsunomiya ◽  
Yoshihiro Saito ◽  
Tomoaki Shinoda ◽  
Ichiro Takasu

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