Industrial heat treatment simulation

Transcription

1 Industrial heat treatment simulation using phase kinetic models in LS-DYNA in combination with the DynaWeld preprocessor Nordic LS-DYNA conference Göteborg till Tobias Loose Ingenieurbüro Tobias Loose, Herdweg 13, D Wössingen, Thomas Klöppel DYNAmore, Industriestraße 2, D Stuttgart, 1

2 INGENIEURBÜRO TOBIAS LOOSE Herdweg 13, D Wössingen Lkr. Karlsruhe E-Post: Mobil: Numerical Simulation for Welding and Heat Treatment since Consulting - Training - Support Software Development and Distribution 2

3 Foto: Edyta Łopatecka Achieve the best results! 3

4 Old fashioned Discoupled Design of Specimen and Process Design of Geometry Design of Process many iterations Request Request functionability and stability under service Quelle: Frank Tangemann zero distortion desired properties 4

5 New fashioned Integrated Design of Specimen and Process Heat Treatment Simualtion Design of Geometry Design of Process Parameter: Request functionability and stability under service process conditions Quelle: Frank Tangemann Distortion Microstructure Hardening depth Hardness few tests Validation and QA 5

6 Example Quenching of a Gear 6

7 Quenching of a Gear Temperature Curve Edge Middle 7

8 Quenching of a Gear Results of Heat Treatment Simulation Martensit (right) Hardness HV (bottom left) Yield (bottom right) 8

9 Heat Treatment Overview Type of heat treatment Quenching Case Hardening Inductive hardening Press hardening Single process steps Heating Thermal Heating Inductive Heating Carburisation Quenching Tempering Design of properties by local change of material properties and microstructure 9

10 Software Requirements for Heat Treatment Simulation Solver robustness performance thermal mechanical electromagnetic multiphase material model LS-DYNA 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 DynaWeld Heat Treatment 10

11 LS-DYNA Material Foto: Edyta Łopatecka with phase kinetic models 11

12 Phase Transformation during Cooling CCT-Diagram Quelle: Bernd Hochholdinger, DYNAmore Swiss 12

13 Phase Kinetic Models Law: Koinstinen-Marburger Tstart: a: Parameter: Start Temperature kinetic faktor Use: MS KM f(temperature) diffusionless transformation Austenit Martensit 13

14 Phase Kinetic Models Law: Oddy Tstart: n: c1: c2: Parameter: Start Temperature form parameter kinetic faktor kinetic exponent based on Avrami equitation Use: f(temperature, time) diffusion-driven transformation Austenitisation 14

15 Phase Kinetic Models Law: Kirkaldy Parameter: Chemical Compositon Grain Size Start Temperature activation energy kinetic factor and exponent Advantage: Needs only grain size and chemical compositon material certificate based on Avrami equitation Use: f(temperature, time) diffusion-driven transformation Austenite Ferite, Perlite, Bainite Disadvantage: Limitation to one steel type and small range of chemical composition 15

16 Phase Kinetic Models Law: based on Avrami equitation extended by Leblond generalized JMAK Jonhson-Mehl-Avrami-Kolmogorov xeq: n: t: f,f': Parameter: Proprotion at equilibrium (T) form parameter (T) kinetic faktor (T) Leblond factor (dt/dt) Use: f(temperature, temperture gradient, time) diffusion-driven transformation Austinitisation, Tempering Austenite Ferite, Perlite, Bainite phase transformation Aluminium PEQ N TAU F, F', 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 16

17 Materials with Phase Kinetic Models in LS-DYNA *MAT_244 / *MAT_UHS_STEEL *MAT_248 / *MAT_BMW Press hardening Laws: Koinstinen Marburger Oddy Kirkaldy fix assignment of laws Boron Steels z.b 22MnB5 based on research from Mats Oldenburger et. al. Lulea Universitet Features: 5 Phases (Austenite, Ferrite, Pearlite, Bainite, Martensite) Shells and Solids Welding features (MAT_244) Austinitisation Austenite decomposition (A F,P,M,B) Phase transformation strain Transformation induced plasticity (TRIP) Hardeness computation Simulation of PROCESS-CHAIN feasible 17

18 Materials with Phase Kinetic Models in LS-DYNA *MAT_254 / *MAT_GENERALIZED_PHASE_CHANGE Heat treatment Welding Laws: Koinstinen Marburger Oddy Kirkaldy generalized JMAK Time criterium list might be extended userdefined assignment of laws all materials Features: 24 Phases Shells, Solids, 2D-shells Welding features Phase transformation strain Transformation induced plasticity (TRIP) Subcycling for phase transformation Tempering Hardeness computation Simulation of PROCESS-CHAIN feasible 18

19 Selected Features: DTEMP Phase transformation calculation temperature requires limit on tempearature step Phase transformation shall not reduce time step of mechanical solver DTEMP = maximum allowed temperature step drives subcycle for phase transformation: 19

20 Selected features: Phase Transformation Strain If Phase A and B have different density in case of phase transformation additional strain arises due to volume change: Phase Transformation Strain. 20

21 *MAT_254 Calibration of Phase Transformation Law given CCT Data LS-DYNA calculation 21

22 Validation Nitschke-Pagel Test Distortion w: Experiment: 0,34 mm Sysweld: 0,32 mm LS-DYNA: 0,34 mm Loose, T.: Einfluß des transienten Schweißvorganges auf Verzug, Eigenspannungen und Stabiltiätsverhalten axial gedrückter Kreiszylinderschalen aus Stahl, Diss, Karlsruhe,

23 KEYWORD *MAT_254 *MAT_GENERALISED_PHASE_CHANGE 23

24 DynaWeld Foto: Edyta Łopatecka Heat Treatment 24

25 DynaWeld Management for High Sofisticated Heat Treatment Materials and Simulation Setup Material DynaWeld Material User defined JMatPro Import and extensions: Base material phase Liquid material phase Tempering phase Flowcurve adjustment WeldWare other material simulation software LS-DYNA Material keyword-file 25

26 DynaWeld Management for High Sofisticated Heat Treatment Materials and Simulation Setup Model Setup DynaWeld Heat Treatment Oven curve Carburization LS-DYNA Mesh keyword-file LS-DYNA Material keyword-file Dokumentation in spreadsheed format HT-Process HT-Parameter HT-Solver Settings LS-DYNA Keyword-files Quenching media Diving LS-DYNA solver run 26

27 DynaWeld Material - Import Settings and Extensions Interfaces 27

28 DynaWeld Material Documentation Spreadsheet DynaWeld-Material-Check Graph for each material parameter 28

29 DynaWeld Heat Treatment - Process 29

30 DynaWeld Heat Treatment - Parameter 30

31 Conclusion LS-DYNA Material Models representing physics within phase kinetics from Process parameter to solver keyword input Succes in industrial applied simulation for manufacturing processes with high sophisticated phiysical phenomena like Heat Treatment DynaWeld 31

32 Mange Tak! Foto: Martin Loose 32