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Tobias LooseIngenieurbüro Tobias Loose, Herdweg 13, D- 75045 Wössingen,[email protected] www.tl-ing.eu
Industrial heat treatment simulation using phase kinetic models in LS-DYNA
in combination with the DynaWeld preprocessor
Nordic LS-DYNA conferenceGöteborg 13.10.16 till 14.10.16
Thomas KlöppelDYNAmore, Industriestraße 2, D-70565 Stuttgart, www.dynamore.de
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Numerical Simulation forWelding and Heat Treatment since 2004
INGENIEURBÜRO TOBIAS LOOSEHerdweg 13, D-75045 Wössingen Lkr. Karlsruhe
E-Post: [email protected] Mobil: +49 176 6126 8671
www.WeldWare.euwww.SimWeld.euwww.DynaWeld.eu
Consulting - Training - SupportSoftware Development and Distribution
www.loose.at
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Foto: Edyta ŁopateckaAchieve the best results!
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Old fashionedDiscoupled Design of Specimen and Process
Designof
Geometry
Request• functionability and
stability under service
Designof
Process
Request• zero distortion• desired properties
many iterations
Quelle: Frank Tangemann
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New fashioned Integrated Design of Specimen and Process
Designof
Geometry
Request• functionability and
stability under service• process conditions
Designof
Process
Validationand QA
few tests
Heat Treatment Simualtion
Quelle: Frank Tangemann
Parameter:• Distortion• Microstructure• Hardening depth• Hardness
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Example Quenching of a Gear
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Quenching of a GearTemperature Curve
EdgeMiddle
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Martensit (right)
Hardness HV (bottom left)
Yield (bottom right)
Quenching of a GearResults of Heat Treatment Simulation
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HeatingThermal HeatingInductive Heating
Quenching
Carburisation
Tempering
Quenching
Case Hardening
Inductive hardening
Press hardening
Heat Treatment Overview
Typeof heat treatment
Single process steps
Design of properties by local change of material properties and microstructure
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Software Requirements for Heat Treatment Simulation
Solver– robustness– performance– thermal – mechanical – electromagnetic– multiphase material model
• with phase transformation• with phase transformation effects
– diffusion simulation with impact on material model
Preprocessor and Environment– material management– easy work and quick setup– automatisation as far as possible– input based on process parameters– Model check and QA
DynaWeldHeat Treatment
LS-DYNA
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LS-DYNA Materialwith phase kinetic modelsFoto: Edyta Łopatecka
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Phase Transformation during CoolingCCT-Diagram
Quelle: Bernd Hochholdinger, DYNAmore Swiss
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Phase Kinetic Models
Law:Koinstinen-Marburger
Parameter:Tstart: Start Temperature MSa: kinetic faktor KM
Use:f(temperature)diffusionless transformation
Austenit → Martensit
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Phase Kinetic Models
Law:Oddy
Parameter:Tstart: Start Temperaturen: form parameterc1: kinetic faktorc2: kinetic exponent
Use:f(temperature, time)diffusion-driven transformation
Austenitisation
based on Avrami equitation
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Phase Kinetic Models
Law:Kirkaldy
Parameter:Chemical CompositonGrain Size→ Start Temperature→ activation energy→ kinetic factor and exponent
Use:f(temperature, time)diffusion-driven transformation
Austenite → Ferite, Perlite, Bainite
Advantage:Needs only grain size and chemical compositon→ material certificate
Disadvantage:Limitation to one steel type and small range of chemical composition
based on Avrami equitation
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Phase Kinetic Models
Law:generalized JMAK
Jonhson-Mehl-Avrami-Kolmogorov
Parameter:xeq: Proprotion at equilibrium (T) PEQn: form parameter (T) Nt: kinetic faktor (T) TAUf,f': Leblond factor (dT/dt) F, F'
Use:f(temperature, temperture gradient, time)diffusion-driven transformation
Austinitisation, TemperingAustenite → Ferite, Perlite, Bainitephase transformation Aluminium
Advantage:no limitation on material type nor chemical composition. Fitting according:temperatur(T) and temperature rate(dT/dt)
Disadvantage:needs calibration on existing CCT or TT
based on Avrami equitationextended by Leblond
,
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Materials with Phase Kinetic Models in LS-DYNA
*MAT_244 / *MAT_UHS_STEEL*MAT_248 / *MAT_BMW
Press hardening Boron Steelsz.B 22MnB5
based on research fromMats Oldenburger et. al.
Lulea Universitet
Laws:Koinstinen MarburgerOddyKirkaldy
fix assignment of laws
Features:5 Phases (Austenite, Ferrite, Pearlite, Bainite, Martensite)Shells and SolidsWelding features (MAT_244)AustinitisationAustenite decomposition (A → F,P,M,B)Phase transformation strainTransformation induced plasticity (TRIP)Hardeness computation
Simulation of PROCESS-CHAIN feasible
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Materials with Phase Kinetic Models in LS-DYNA
*MAT_254 / *MAT_GENERALIZED_PHASE_CHANGE
Heat treatmentWelding
all materials
Laws:Koinstinen MarburgerOddyKirkaldygeneralized JMAKTime criteriumlist might be extended
userdefined assignment of laws
Features:24 PhasesShells, Solids, 2D-shellsWelding featuresPhase transformation strainTransformation induced plasticity (TRIP)Subcycling for phase transformationTemperingHardeness computation
Simulation of PROCESS-CHAIN feasible
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Selected Features: DTEMP
Phase transformation calculation temperature requires limit on tempearature stepPhase transformation shall not reduce time step of mechanical solverDTEMP = maximum allowed temperature step drives subcycle for phase transformation:
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Selected features: Phase Transformation Strain
If Phase A and B have different densityin case of phase transformationadditional strain arises due to volume change:Phase Transformation Strain.
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*MAT_254 Calibration of Phase Transformation Law
given CCT Data
LS-DYNA calculation
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Validation Nitschke-Pagel Test
Distortion w:Experiment: 0,34 mmSysweld: 0,32 mmLS-DYNA: 0,34 mm
Loose, T.: Einfluß des transienten Schweißvorganges auf Verzug, Eigenspannungen und Stabiltiätsverhalten axial gedrückter Kreiszylinderschalenaus Stahl, Diss, Karlsruhe, 2008
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KEYWORD *MAT_254*MAT_GENERALISED_PHASE_CHANGE
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DynaWeldHeat Treatment
Foto: Edyta Łopatecka
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DynaWeld – Management forHigh Sofisticated Heat Treatment Materials and Simulation Setup
Material DynaWeld Material User defined
Import and extensions:Base material phaseLiquid material phaseTempering phaseFlowcurve adjustment
JMatPro
WeldWare
other material simulation software
LS-DYNAMaterial keyword-file
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DynaWeld – Management for High Sofisticated Heat Treatment Materials and Simulation Setup
Model SetupDynaWeld
Heat TreatmentOven curve
HT-ProcessHT-ParameterHT-Solver Settings
Carburization
Quenching media
Diving
LS-DYNA Keyword-files
Dokumentationin spreadsheed format
LS-DYNA solver run
LS-DYNAMesh keyword-file
LS-DYNAMaterial keyword-file
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DynaWeld Material - Import
Interfaces
Settings and Extensions
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DynaWeld Material – DocumentationSpreadsheet DynaWeld-Material-Check
Graph for each material parameter
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DynaWeld Heat Treatment - Process
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DynaWeld Heat Treatment - Parameter
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Conclusion
LS-DYNA
DynaWeld
from Process parameter to solver
keyword input
Material Models representing physics within phase kinetics
Succes in industrial applied
simulation for manufacturing
processes with high sophisticated
phiysical phenomena like
Heat Treatment
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Mange Tak!
Foto: Martin Loose
