Forward Slip and Backward Slip in Radial Ring Rolling Process

2013 ◽  
Vol 423-426 ◽  
pp. 820-823 ◽  
Author(s):  
Yan Liu ◽  
Qiang Wang ◽  
Dong Mei Cai
Keyword(s):  
Rolling Process ◽  
Tangential Component ◽  
Ring Rolling ◽  
Forward Slip ◽  
Slip Coefficient ◽  
Relative Slip ◽  
Speed Difference ◽  
Slip Tendency ◽  
Ring Rolling Process

During the process of radial ring rolling, relative slip or relative slip tendency occurs on the interface between the ring and the rolls. Research on the relative slip or relative slip tendency plays an important role on reducing friction to ensure the ring rolling smoothly. In this paper, the reason of relative slip or relative slip tendency is investigated that there is speed difference between tangential component of the ring and linear velocity of the rolls. According to speed difference, slip types of the interface are classified. Forward slip coefficient and backward slip coefficient are defined and derived and relations between them are studied. Comparison between the new method and the previous one is conducted via case study, which proves the rationality and effectiveness.

Speed Roll Laws Influence in a Ring Rolling Process

2013 ◽  
Vol 554-557 ◽  
pp. 337-344 ◽  
Author(s):  
Luca Giorleo ◽  
Elisabetta Ceretti ◽  
Claudio Giardini
Keyword(s):  
Numerical Approach ◽  
Rolling Process ◽  
Ring Rolling ◽  
Roll Speed ◽  
Forming Process ◽  
Industrial Case Study ◽  
Ring Shape ◽  
Deformation Processes ◽  
Ring Rolling Process

Ring Rolling is a complex hot forming process used for the production of shaped rings, seamless and axis symmetrical workpieces. The main advantage of workpieces produced by ring rolling, compared to other technological processes, is given by the size and orientation of grains, especially on the worked surface which give to the final product excellent mechanical properties. In this process different rolls (Idle, Axial, Guide and Driver) are involved in generating the desired ring shape. Because each roll is characterized by a speed law that could be set independently by the speed law imposed to the other rolls an optimization is more critical compared with other deformation processes. Usually in industrial environment a milling curve is introduced in order to correlate the Idle and Axial roll displacement, however it must be underlined that different milling curves lead to different loads and energy for ring realization.In this work an industrial case study was modeled by a numerical approach: different milling curves characterized by different Idle and Axial roll speeds laws (constant, linear and quadratic) were designed and simulated. The results were compared in order to identify the best set of Idle and Axial roll speed laws that guarantee a good quality produced ring (lower fishtail) with lower manufacturing loads and energy.

Key Technologies for 3D-FE Modeling of Radial-Axial Ring Rolling Process

2008 ◽  
Vol 575-578 ◽  
pp. 367-372 ◽  
Author(s):  
L.G. Guo ◽  
He Yang
Keyword(s):  
Modeling And Simulation ◽  
Optimum Design ◽  
Rolling Process ◽  
Ring Rolling ◽  
Fe Modeling ◽  
Precise Control ◽  
Key Technologies ◽  
Axial Ring ◽  
Forming Characteristics ◽  
Ring Rolling Process

Nowadays, 3D-FE Modeling and simulation is an indispensable method for the optimum design and precise control of radial-axial ring rolling process for its complexities. In this paper, the unique forming characteristics of radial-axial ring rolling have first been summarized, and then some key technologies for 3D-FE modeling of the process have been presented and their solution schemes have been given out, lastly the modeling and simulation of radial-axial ring rolling process have been realized using elastic-plastic dynamic explicit procedure under ABAQUS environment. The work provides an important basis and platform for the future investigations, such as forming mechanism and laws, process optimum design and precise control.

Effect of the Guide-Roll Positional Angle to the Stability of Radial Ring Rolling

2007 ◽  
Vol 561-565 ◽  
pp. 1875-1878 ◽  
Author(s):  
Yong Xing Hao ◽  
Lin Hua ◽  
Gui Shan Chen ◽  
Dao Ming Wang
Keyword(s):  
Position Angle ◽  
Rolling Process ◽  
Ring Rolling ◽  
Positional Angle ◽  
The Mean ◽  
The Stability ◽  
Ring Rolling Mill ◽  
Ring Rolling Process ◽  
Ring Blank ◽  
Evaluating Method

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.

scholarly journals Investigation of Slip Occurrence in the Ring Rolling Process

2019 ◽  
Vol 291 ◽  
pp. 02006
Author(s):  
Andrzej Gontarz ◽  
Piotr Surdacki
Keyword(s):  
Wall Thickness ◽  
Failure Modes ◽  
Rolling Process ◽  
Ring Rolling ◽  
Thickness Reduction ◽  
Main Stage ◽  
Forming Process ◽  
Limit Values ◽  
Ring Shape ◽  
Ring Rolling Process

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.

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