During hot metal forming, the temperature variation and plastic deformation affect each other considerably. In the present investigation, ring rolling of hot steel is simulated by using a three-dimensional thermo-coupled rigid-viscoplastic finite element method. A new term is added to the functional in the variational approach to consider the influence of the frictional torque of the mandrel bearing, and the coupled thermal-mechanical simulation is performed by the iteration between the rigid-viscoplastic finite element analysis and the thermal finite element analysis. Since the deformation region and the severe temperature changes are restricted to the vicinity of the roll gap, only a ring segment and parts of the rolls are analyzed using a steady-state treatment to save computation time. Roll force and torque, width spread, temperature distributions, the distributions of strain and strain rate and the distributions of relative velocity and stress at the roll surfaces are obtained. The results show that the angular velocity of the driven roll has a significant influence on the temperature variations in the ring and the rolls, to which attention should be paid in the design of the process. The method presented can also be used to analyze other forming processes such as unsymmetrical plate rolling, symmetric rolling, and extrusion.

1.
Johnson
W.
, and
Needham
G.
, “
Experiments on Ring Rolling
,”
Int. J. Mech. Sci.
, Vol.
10
, pp.
95
113
,
1968
.
2.
Johnson
W.
, and
Needham
G.
, “
Plastic Hinges in Ring Indentation in Relation to Ring Rolling
,”
Int. J. Mech. Sci.
, Vol.
10
, pp.
487
490
,
1968
.
3.
Johnson
W.
,
Macleod
I.
, and
Needham
G.
, “
An Experimental Investigation into the Process of Ring or Metal Tyre Rolling
,”
Int. J. Mech. Sci.
, Vol.
10
, pp.
455
466
,
1968
.
4.
Mamalis
A. G.
,
Johnson
W.
, and
Hawkyard
J. B.
, “
On the Pressure Distribution between Stock and Rolls in Ring Rolling
,”
J. Mech. Eng. Sci
, Vol.
18
, No.
4
, pp.
184
195
,
1976
.
5.
Mamalis
A. G.
,
Johnson
W.
, and
Hawkyard
J. B.
, “
Pressure Distribution, Roll Force and Torque in Cold Ring Rolling
,”
J. Mech. Eng. Sci.
, Vol.
18
, No.
4
, pp.
196
209
,
1976
.
6.
Mamalis
A. G.
,
Hawkyard
J. B.
, and
Johnson
W.
, “
Spread and Flow Patterns in Ring Rolling
,”
Int. J. Mech. Sci.
, Vol.
18
, pp.
11
16
,
1976
.
7.
Hawkyard, J. B., and Ingham, P. M., “An Investigation into Profile Ring Rolling,” Proc. 1st Int. Conf. on ROMP, London, UK, pp. 309–320, 1979.
8.
Hawkyard, J. B., and Moussa, G., “Studies of Profile Development and Roll Force in Profile Ring Rolling,” Proc. 3rd Int. Conf. on ROMP, Kyoto, Japan, pp. 301–310, 1984.
9.
Yang, D. Y., Ryoo, J. S., Choi, J. C., and Johnson, W., “Analysis of Roll Torque in Profile Ring Rolling of L-Sections,” Proc. 21st Int. Conf. on MTDR, London, pp. 69–74, 1981.
10.
Ryoo, J. S., Yang, D. Y., and Johnson, W., “Ring Rolling: The Inclusion of Pressure Roll Speed for Estimating Torque by Using a Velocity Superposition Method,” Proc. 24th Int. Conf. on MTDR, Manchester, pp. 19–24, 1983.
11.
Yang
D. Y.
, and
Ryoo
J. S.
, “
An Investigation into the Relationship between Torque and Load in Ring Rolling
,”
ASME JOURNAL OF ENGINEERING FOR INDUSTRY
, Vol.
109
, Aug., pp.
190
196
,
1987
.
12.
Hayama
M.
, “
Theoretical Analysis on Ring Rolling of Plain Ring
,”
Bull. Facu. Eng. Yokohama National Univ.
, Vol.
31
, March, pp.
131
153
,
1982
.
13.
Lugora
C. F.
, and
Bramley
A. N.
, “
Analysis of Spread in Ring Rolling
,”
Int. J. Mech. Sci.
, Vol.
29
, pp.
149
157
,
1987
.
14.
Doege
E.
, and
Aboutour
M.
, “
Simulation of Ring Rolling Process
,”
Proc. 2nd ICTP, Advanced Technology of Plasticity
, Vol.
2
, Germany, pp.
817
824
,
1987
.
15.
Yang
D. Y.
, and
Kim
K. H.
, “
Rigid-Plastic Finite Element Analysis of Plane Strain Ring Rolling
,”
Int. J. Mech. Sci.
, Vol.
30
, pp.
571
580
,
1988
.
16.
Hu
Y. K.
, and
Liu
W. K.
, “
ALE Finite Element Formulation for Ring Rolling Analysis
,”
Int. J. Numer. Methods Eng.
, Vol.
33
, pp.
1217
1236
,
1992
.
17.
Tszeng
T. C.
, and
Altan
T.
, “
Investigation of Ring Rolling by Pseudo Plane-Strain FEM Analysis
,”
J. Mater. Process. Technol.
, Vol.
27
, pp.
151
161
,
1991
.
18.
Xu
S. G.
,
Lian
J. C.
, and
Hawkyard
J. B.
, “
Simulation of Ring Rolling Using a Rigid-Plastic Finite Element Model
,”
Int. J. Mech. Sci.
, Vol.
33
, pp.
393
401
,
1991
.
19.
Kim
N.
,
Machida
S.
, and
Kobayashi
S.
, “
Ring Rolling Process Simulation by the Three Dimensional Finite Element Method
,”
Int. J. Mach. Tools Manufa.
, Vol.
30
, pp.
569
577
,
1990
.
20.
Yang
D. Y.
,
Kim
K. H.
, and
Hawkyard
J. B.
, “
Simulation of T-Section Profile Ring Rolling by the 3-D Rigid-Plastic Finite Element Method
,”
Int. J. Mech. Sci.
, Vol.
33
, pp.
541
550
,
1991
.
21.
Kikuchi, N., Finite Element Methods in Mechanics, Cambridge University Press, Cambridge, 1986.
22.
Hughes
T. J. R.
, “
A Simple Scheme for Developing ‘Upwind’ Finite Elements
,”
Int. J. Numer. Methods Eng.
, Vol.
12
, pp.
1359
1365
,
1978
.
23.
Shida
S.
, “
Empirical Formula of Flow-Stress of Carbon Steel
,”
J. Jap. Soc. Technol. Plast.
, Vol.
10
, pp.
610
617
,
1969
, in Japanese.
24.
Rebelo
N.
, and
Kobayashi
S.
, “
A Coupled Analysis of Viscoplastic Deformation and Heat Transfer-2
,”
Int. J. Mech. Sci.
, Vol.
22
, pp.
707
718
,
1980
.
25.
Im
Y. T.
, “
Investigation of Heat Transfer and Simulation of Metal Flow in Hot Upsetting
,”
JOURNAL OF ENGINEERING FOR INDUSTRY
, ASME Vol.
111
, pp.
337
344
,
1989
.
26.
Xu, S. G., “Finite Element Analysis of Ring Rolling Process, Advanced Technology of Plasticity 1993,” Proc. 4th ICTP, Vol. 3, pp. 1413–1418, International Academic Publishers.
27.
Xu
S. G.
, and
Cao
Q. X.
, “
Numerical Simulation of the Microstructure in the Ring Rolling of Hot Steel
,”
J. Mater. Process. Technol.
, Vol.
43
, pp.
221
235
,
1994
.
28.
Pietrzyk
M.
,
Roucoules
C.
, and
Hodgson
P. D.
, “
Modelling the Thermomechanical and Microstructure Evolution During Rolling of a Nb HSLA Steel
,”
ISIJ International
, Vol.
35
, pp.
531
541
.
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