advanced numerical and physical simulation of the ring rolling process
Transcript of advanced numerical and physical simulation of the ring rolling process
ADVANCED NUMERICAL
AND PHYSICAL SIMULATION
OF THE RING ROLLING PROCESS
S. Andrietti1, J.-L. Chenot1,2, P. Lasne1,
1 Transvalor SA, France 2 CEMEF - Mines ParisTech, France
AeroMat’2014 – S. Andrietti et al. 1
Outline
• Introduction
• Thermo-mechanical model & FE resolution
• Examples of numerical simulation with FORGE®
• Metallurgical aspects
• Conclusions
2 AeroMat’2014 – S. Andrietti et al.
Introduction • Applications of ring rolling in many industrial fields:
– Aerospace
– Automotive
– Nuclear
– Railroad, Oil & Gas
– Wind Power
• Sophisticated process:
– Due to kinematics
– Several independent rolls
– Accurate piloting is crucial
3 AeroMat’2014 – S. Andrietti et al.
Industrial issues
• Rolling mill piloting
• Process instabilities : ring climbing phenomenon, offset
• Workpiece properties : effective strain and grain flow
• Prevent defects : underfilling, folds, fishtail, …
• Prediction of the microstructure
=> Virtual factory from ingot to final ring.
4 AeroMat’2014 – S. Andrietti et al.
• Introduction
• Thermo-mechanical model & FE resolution
• Examples of numerical simulation with FORGE®
• Metallurgical aspects
• Conclusions
5 AeroMat’2014 – S. Andrietti et al.
• Constitutive equations
– Elasto-viscoplastic:
– Elasticity:
– Viscoplasticity:
Example of power law:
6
e p th
( ) (3 2 ) 2e e e e e eJdtrace T I
dt
0
2' ( , , )
3
p
T
1
' 2 ( , ) 3m
pK T
AeroMat’2014 – S. Andrietti et al.
• Friction modeling:
– Example « Coulomb viscoplastic »:
• Thermal coupling
7
1 fp
f n v v
( ( )) : 0pdTc div kgrad T r
dt
AeroMat’2014 – S. Andrietti et al.
8
• Time discretization:
– Time increments t for non-stationary processes
– Implicit formulation for the mechanical equilibrium at each
time step
• Finite element discretization:
– Use of P1+/P1 linear tetrahedral elements
– Unknows : Velocity (v) , Pressure (p) , Temperature (T)
• Equation solving:
– Iterative method for non-linear system
– Solver supports high parallel computing (up to 64 cores)
AeroMat’2014 – S. Andrietti et al.
• Arbitrary Lagrangian Eulerian (ALE) formulation:
– Use of a structured mesh with refinement in angular
sectors
– Next trends : dual-mesh technique, self-adaptive
remeshing
9 AeroMat’2014 – S. Andrietti et al.
10
• Introduction
• Thermo-mechanical model & FE resolution
• Examples of numerical simulation with FORGE®
• Metallurgical aspects
• Conclusions
Aeromat’2014 – S. Andrietti et al.
Typical defect prediction
12 AeroMat’2014 – S. Andrietti et al.
Underfilling defect
Fishtail defect
Cou
rte
sy o
f M
ura
ro S
pa
Rolling mill piloting
• Ring centering :
– Use of force-driven (or torque) guide rolls
– Keep the ring’s centroid along X-axis by applying a
scalar constraint
• Piloting mode :
– « conventional » : displacements of mandrel & axial rolls
are set based on pre-defined rolling curves
– « innovative » : coupling with real-time process data 14 AeroMat’2014 – S. Andrietti et al.
15
Conventional piloting
King roll : constant rotation speed
Mandrel & axial rolls : automatic rotation speed
Standard rolling curves :
• Ring Growth Speed vs Outer Diameter
• Ring Height vs Thickness
AeroMat’2014 – S. Andrietti et al.
Ring thickness
Rin
g h
eig
ht
17
Innovative piloting
Collaborative work with Muraro Spa (Italy)
Displacements of rolls & cones are function of time
according to the real evolution of the ring’s parameters
• Diameter – Thickness – Height
• Linear velocity - Rotation speed
• Force - Torque
AeroMat’2014 – S. Andrietti et al.
General principle of the external piloting
18
Innovative piloting - Results
AeroMat’2014 – S. Andrietti et al.
Stainless steel bearing ring
Courtesy of Muraro Spa
20
• Introduction
• Thermo-mechanical model & FE resolution
• Examples of numerical simulation with FORGE®
• Metallurgical aspects
• Conclusions
Aeromat’2014 – S. Andrietti et al.
Heat treatment capabilities
21 AeroMat’2014 – S. Andrietti et al.
• Various heat treatment operations can be simulated:
– Austenitization, carburizing, nitriding
– Quenching, tempering
– Induction heating, induction hardening
• Standard outputs:
– Phase transformation (for steel), dimensional variations
– Final hardness & residual stress
• Example:
– Water+Polymer quenching of a steel ring
22 AeroMat’2014 – S. Andrietti et al.
AISI 4140 Steel - HTC conditions
Vickers hardness distribution vs Experimental measurements
Co
urt
esy
of
Fris
a Fo
rjad
os
Quenching - Results
23
Microstructure evolution
JMAK semi-empirical approach for recristallization
AeroMat’2014 – S. Andrietti et al.
Dynamic : nucleation and growth during
deformation
Meta-dynamic : nucleation during
deformation and growth after deformation
Static : nucleation and growth after
deformation
For given constant conditions
Material data for recristallization
• Low carbon steel : SAE 1035, …
• Austenitic stainless steels : 316L, …
• Ni steels / Mn steels / Cr steels
• Ni-Cr-Mo / Mn-Cr / Cr-Mo / Mn-Si steels (SAE 9310, SAE 5120, SAE 4140, SAE 1536, …)
• Nickel based alloy : Inconel718, Waspaloy
• Or User data
24 AeroMat’2014 – S. Andrietti et al.
AeroMat’2014 – S. Andrietti et al. 25
Recristallization during ring rolling
Grain size evolution with sensors Strain & Strain rate vs Time
29
Recristallization model – Full field approach
AeroMat’2014 – S. Andrietti et al.
Adaptive anisotropic mesh
Representative Volume Element
Modelling of grain growth (left) and static recrystallization (right) in 304L austenitic stainless steel
Conclusions
• Numerical simulations of complex ring rolling process
providing reliable results (final shape, grain flow,
defects, strain-temperature-stress-hardness, …)
• An innovative & efficient new piloting method to
reproduce the industrial practice
• Intensive work for final microstructure prediction using
mesoscale modeling
• Perspectives : use multi-objective optimization engine
applicable to any sort of process design
30 Aeromat’2014 – S. Andrietti et al.
THANK YOU FOR YOUR ATTENTION
Stéphane Andrietti Director of Software Production Department
Transvalor SA
Email : [email protected]
Web site : www.transvalor.com
AeroMat’2014 – S. Andrietti et al. 31
Patrice Lasne Expert Engineering Department
Transvalor SA
Email : [email protected]
Web site : www.transvalor.com
Professor Jean-Loup Chenot Transvalor Scientific Director
Email : [email protected]
www.transvalor.com
www.cemef.mines-paristech.fr