Influence of the Intermediate Annealing on Deformation Ability of the Cold Rolled Ring

2014 ◽  
Vol 893 ◽  
pp. 644-648
Author(s):  
Wen Ting Wei ◽  
Xun Peng Qin ◽  
Song Deng

This paper studies the influence of the intermediate annealing on deformation ability of the cold rolled ring. The results show that: intermediate annealing can improve the ability of plastic deformation of the cold rolled ring, ring rupture occurred after 62.5% thickness reduction, on the other side the ring suffering intermediate annealing still be intact by rolling to upon 64.8% thickness reduction. The mechanism of the intermediate annealing improving deformation ability of cold rolled ring is explored by using optical microscopy, scanning electron microscopy, micro hardness tester and other materials characterization methods. It is found that after intermediate annealing, the amount of carbide particles significantly reduce and the hardness decrease. Meanwhile, dissolution of partial carbides occur during the cold ring rolling process, and with the increasing of the cold rolling deformation, the quantity of the dissolution of cementite in pearlite will increase, which resulting in the improvement of the deformability of the cold rolled ring.

2019 ◽  
Vol 291 ◽  
pp. 02006
Author(s):  
Andrzej Gontarz ◽  
Piotr Surdacki

Ring rolling is a hot forming process for producing rings that have large diameters when compared to their cross sections. This process is very dynamic and involves considerable variations in ring shape and size. One of the failure modes in ring rolling processes is slip that occurs when a thickness reduction, exceeds the limit value. The thickness reduction depends on the tool speed and dimensions as well as ring size, and varies over time. This paper reports results of a study investigating the thickness reduction with respect to slip occurrence. In terms of wall thickness reduction, the process can be divided into three distinct stages (excluding the sizing stage): (i) initial stage corresponding to the first revolution of the roll, (ii) main stage, when the proper ring rolling takes place, (iii) final stage, when the main roll does not move in an axial direction but the ring is being formed during one revolution of the tool. It has been found that the most slip-prone moment is the end of the second and the beginning of the third stage of the ring rolling process, when the wall thickness reduction is the highest. Based on a comparison of the calculated thickness reduction and its limit values, it could be predicted whether slip would occur, and if so – in what stage of the rolling process. Numerical results and experimental findings are in good agreement.


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.


2011 ◽  
Vol 291-294 ◽  
pp. 297-305
Author(s):  
Li Bo Pan ◽  
Lin Hua ◽  
Dong Sheng Qian

Cold ring rolling is a kind of advanced manufacturing technology. During rolling process the ring may be collapsed or deformed unexpectedly under the pressure of guide roll because the stiffness condition is not met. The force of guide roll to ring was obtained by analyzing the forces to ring. The stiffness condition expressions of ring during rolling were shown after constructing the mechanical model. According to the expressions, the effects of several parameters on the stiffness condition were discussed and analyzed in detail, such as position angle of guide roll, friction coefficient and feed rate, etc, which revealed essential reasons of some cases occurring in cold ring rolling. Then the ring blank dimension was deduced based on the ring stiffness condition. The dimensions of ring blank should meet a relationship to ensure the ring stiffness condition to be satisfied during rolling, which can conduct the practical manufacturing effectively. Finally the analysis and effect laws were proved by finite element simulation experiments. The researches could be helpful to control parameter in cold ring rolling effectively for high quality products.


2013 ◽  
Vol 773 ◽  
pp. 309-315 ◽  
Author(s):  
Lian Jie Li ◽  
Xiao Dong Luo ◽  
Yong Xiang Zhu

In this paper, a 3D elastic-plastic and coupled thermo-mechanical FE model of radial ring rolling of 6061 aluminum alloy is developed, and the hot rolling process with different the rotational speed of driver roll n is simulated by using the dynamic explicit code ABAQUS/Explicit. The influence laws of the rotational speed of driver roll on the uniformity of strain and temperature distribution (STD), fishtail coefficient, roll force, contact area and roll moment are revealed respectively. One optimum n is obtained, under which SDT is relatively uniform; meanwhile, another optimum n is obtained, under which the quality of end-plane of the rolled ring is the best. The result can provide a valuable guideline to research and optimum of the hot ring rolling of aluminum alloys.


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.


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

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