This document describes a finite element analysis of a rolling process. It provides background on rolling and finite element analysis. It then details the initial basic simulation model created with a 2D deformable plate and analytical rigid roller. Next, it describes a sheet simulation model provided by industry with specific geometry and material properties. The sheet model is used to analyze von mises stress, pressure, and equivalent plastic strain distributions. Finally, it examines the variation of residual stresses with changes to coefficient of friction, plate feed velocity, and roller velocity to determine optimal parameters that minimize residual stress. Future work is needed to address excessive deformation observed in the shell model.

1. FEM ANALYSIS
OF
ROLLING PROCESS
DEPARTMENT OF MECHANICAL ENGINEERING, CKPCET
Prepared by:
Varun V. Joshi (100093119001)
Aditya A. Patel (090090119003)
Chetan K. Anghan (090090119006)
Abhishek A. Mukherjee (090090119010)
Guided By :
Prof. Chaitanya K. Desai
Company :

2. 2
INTRODUCTION
 When metal passes through rolls, metal starts deforming and stress builds up at
arc of contact. There is residual stress remaining within the rolled product post
rolling.
 Finite Element Method (FEM) Analysis is a method of analysis for numerical
solution of field problems. A field problem requires that we determine spatial
distribution of one or more dependent variables.
 In our project, we are concerned with cold rolling process only and intend to
obtain the influence of various parameters such as Co-efficient of friction, Plate
feed speed and Roller Velocity on outputs like Von-Mises Stress, PEEQ &
Pressure, whose distributions have already been obtained through different
inputs using FEM software.
FEM ANALYSIS OF ROLLING PROCESS

3. 3
COMPANY PROFILE
 ESSAR Steel, Hazira is a name renowned within the Rolling Industry.
 It has the most vast amount of rolling facilities in the country and the various
complexes that are involved in the Rolling process are as follows :
 Iron Making Facility
 Hot Roll Mill
 Cold Roll Mill
 In the Cold Roll Mill Complex we observed the following types of Roll Mills
 5-Stand Tandem Mill
 4-High Single Pass Reversing Mill
FEM ANALYSIS OF ROLLING PROCESS

4. 4
LITERATURE REVIEW
Sr. No TITLE YOP
FEM ANALYSIS OF ROLLING PROCESS
1
SIMULATION OF PLANE-STRAIN ROLLING BY THE RIGID-PLASTIC FINITE
ELEMENT METHOD
1981
2
SIMULATION OF THE COLD ROLLING OF STRIP USING AN ELASTIC-PLASTIC
FINITE ELEMENT TECHNIQUE
1985
3
A RIGID-PLASTIC FINITE ELEMENT ANALYSIS OF TEMPER ROLLING
PROCESS
2002
4
ELASTO-PLASTIC FINITE ELEMENT SIMULATION OF A SYMMETRICAL
PLATE ROLLING USING AN ALE APPROACH
2006
5
INVESTIGATION OF INFLUENCE PARAMETERS ON THE HOT ROLLING
PROCESS USING FINITE ELEMENT METHOD
2010
6 ROLLING MILL ROLL DESIGN 2003
7
NON LINEAR FINITE ELEMENT METHOD SIMULATION AND MODELING OF
COLD AND HOT ROLLING PROCESSES.
2007

5. 5
CLASSICAL APPROACH TO ROLLING
The formulation of the problem based on classic approach is done by SLAB
METHOD.
FEM ANALYSIS OF ROLLING PROCESS

6. 6
FINITE ELEMENT ANALYSIS
Before we proceed to the formulation of problems and their simulation there are
some basic concepts that one should be familiar with:
 QUASI-STATIC SIMULATIONS USING EXPLICIT DYNAMICS
 MASS SCALING
 ALE method
 Element: CPE4R(4 node bilinear plain strain , quadrilateral , reduced
integration, hourglass control)
FEM ANALYSIS OF ROLLING PROCESS

7. 7
FEA ROLLING ASSUMPTIONS
These are the assumptions that we have taken in our simulations:
 The arc of contact between the rolls and the metal is a part of a circle.
 The coefficient of friction, μ, is constant in simulation, but in actual
scenario, μ varies along the arc of contact.
 The metal is considered to deform plastically during rolling.
 The volume of metal is constant before and after rolling. In actual scenario,
the volume might decrease a little bit due to close-up of pores.
 The velocity of the rolls is assumed to be constant.
 The metal only extends in the rolling direction and no extension in the
width of the material.
 The cross sectional area normal to the rolling direction is not distorted.
FEM ANALYSIS OF ROLLING PROCESS

8. 8
INITIAL BASIC SIMULATION MODEL
When we went to the industry, they asked us to formulate a basic simulation
model. This was the simulation model we had formed.
2D Deformable plate
Analytical Rigid Wire
FEM ANALYSIS OF ROLLING PROCESS

9. 9
INITIAL BASIC SIMULATION MODEL
FEM ANALYSIS OF ROLLING PROCESS

10. 10
INITIAL BASIC SIMULATION MODEL
FEM ANALYSIS OF ROLLING PROCESS
Reference
Point
Point of Instance

11. 11
INITIAL BASIC SIMULATION MODEL
FEM ANALYSIS OF ROLLING PROCESS
Roller Fixed
Upward Movement
restricted
Plate Feed
Velocity

12. 12
INITIAL BASIC SIMULATION MODEL
This is the ALE meshed part. Element used is CPE4R. Total
no. of elements is 460.
FEM ANALYSIS OF ROLLING PROCESS

13. 13
IBSM - SOLUTION
FEM ANALYSIS OF ROLLING PROCESS

14. 14
SHEET SIMULATION MODEL
Based on our Initial Basic Simulation Model, the industry provided us with the
following data.
Length : 1500 mm
Initial Sheet Thickness : 5 mm
Final Sheet Thickness : 4 mm
Sheet Feed Velocity : 1.5 m/s
Roller Diameter : 380 mm
Roller Velocity: 200 MPM (20 Rad/s)
Initial Material Hardness : 50-60 HRB
Post-Rolling Material Hardness : 90 HRB
Post-Annealing Material Hardness : 60 HRB
FEM ANALYSIS OF ROLLING PROCESS
c

15. 15
SHEET SIMULATION MODEL
The further steps are to be carried out in a similar manner to the way the plate
problem was formulated.
FEM ANALYSIS OF ROLLING PROCESS

16. 16
SHEET SIMULATION MODEL
FEM ANALYSIS OF ROLLING PROCESS

17. 17
SHEET – VMS DISTRIBUTION
FEM ANALYSIS OF ROLLING PROCESS

18. 18
SHEET – PEEQ DISTRIBUTION
FEM ANALYSIS OF ROLLING PROCESS

19. 19
SHEET - PRESSURE DISTRIBUTION
450
400
350
300
250
200
150
100
50
0
-50
Pressure Distribution along Arc of Contact
0 2.3 4.53 6.7 8.8 11 13.13 15.27 17.42 19.55 21.73 23.89 26.07 28.28 30.48 32.7
Stress
True distance along path
Pressure
FEM ANALYSIS OF ROLLING PROCESS

20. 20
VARIATION IN RESIDUAL STRESSES
 As seen in earlier slides, we obtained the Von-Mises Stress distribution.
Once the Roll force is removed, the stress remaining in the Sheet may be
considered as Residual Stress.
 Now we proceed to see the variation in the residual stresses based on the
following parameters:
•Co-efficient of friction f
•Plate Feed Velocity Vp
•Roller Velocity Vr
FEM ANALYSIS OF ROLLING PROCESS

21. 21
CO-EFFICIENT OF FRICTION f
200
195
190
185
180
175
170
165
160
155
150
Residual Stress v/s Co-eff of Friction f
0.2 0.25 0.3 0.35 0.4 0.45
Von Mises / Residual Stresses
Co-Efficient of Friction f
Residual Stresses
Residual stresses initially increase with increase in Co-efficient of
Friction f upto value = 0.35 and then decreases
FEM ANALYSIS OF ROLLING PROCESS

22. 22
PLATE FEED VELOCITY VP
200
150
100
50
0
Residual Stresses v/s Vp
0.25 0.5 0.75 1.25 1.5 1.75
Von-Mises / Residual Stresses
Plate Feed Velocity Vp
Residual Stresses
Residual stresses decreases with increase in plate feed velocity Vp upto
value = 1.5 and then has a sudden increase.
FEM ANALYSIS OF ROLLING PROCESS

23. 23
ROLLER VELOCITY VR
155
150
145
140
135
130
Residual Stresses v/s VR
7 8 9 9.5 10 10.5
Von-Mises / Residual Stresses
Velocity of Roller Vr
Residual Stresses
Residual stresses remains more or less constant with increase in plate
feed velocity Vp, but experiences a sudden drop at value = 9 and then
again follows the earlier established trend.
FEM ANALYSIS OF ROLLING PROCESS

24. 24
OPTIMUM PARAMETERS
Based on all the above graphs, we may conclude that there is a
most optimum combination of parameters which would result in
an overall reduction in the residual stresses.
Co-efficient of Friction f = 0.45
Velocity of Plate Feed VP = 1.5 m/s
Velocity of Roller VR = 9 rad/s
FEM ANALYSIS OF ROLLING PROCESS

25. 25
SCOPE OF FUTUREWORK
When we formulated the shell problem, in the job analysis stage we found
excessive deformation in the roller outer surface and the plate. This was
perhaps due to incorrect load and boundary conditions that we had applied. In
spite of our best efforts, we were unable to remove and eliminate the error and
hence there remains a scope for future work in that direction.
FEM ANALYSIS OF ROLLING PROCESS

26. THANK YOU