using phase kinetic models in LS-DYNA in combination with ... · 1 Tobias Loose Ingenieurbüro...

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Tobias LooseIngenieurbüro Tobias Loose, Herdweg 13, D- 75045 Wössingen,loose@tl-ing.de 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: loose@tl-ing.de 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