DEFORM Simulation Results 2D Hot Forging and Air Cool of Gear Tooth Geometry

1. DEFORM Simulation Results2D Hot Forging and Air Cool of Gear Tooth Geometry Holly Quinn 12/04/2010

2. 2D Axisymmetric Model Workpiece (Yellow) is Plastic and 2200°F Top and Bottom Dies are Rigid. All pieces are 300°F. Workpiece will be re-meshed when interference exceeds 0.00099. Initial Contact Pairs: 1. WP to Bottom Die WP to Top Die Top Die Workpiece Bottom Die DEFORM Model

3. Forging Simulation Setup and Results

4. Main Axisymmetric Geometry Modes Deformation Heat Transfer Step Settings Starting Step = -1 Number of Steps = 100 1 Step = 0.01” Die Displacement Max Strain in WP/step = 0.1 Primary Die = Top Die Iteration Settings Solver = Skyline Iteration Method = Newton-Raphson Convergence Errors 0.001 for Velocity 0.01 for Force Forging Simulation Settings • Process Conditions • Heat Transfer • Environment Temperature = 68F • Convection Coefficient=5.787e-6 But/sec/in2F • Diffusion • Environment Atom Content = 1.69% atm • Reaction rate coefficient = 1e-5 in/sec • Advanced • Contact Error Difference Tolerations = 0.0009

5. Materials Top Die Workpiece Bottom Die

6. Temperature, Final Time step

7. Flash Flash Displacement

8. Effective Stress

9. Effective Strain

10. Effective Strain Rate

11. FlowNet Tracking of Material Flow

12. Two Areas examined: Points within gear “core” Points 6, 18, 21 Points near exterior of gear tooth Points 14, 15, 16 Grain Orientation Plot Average Grain Size from beginning to end of forging (Step 1 – 43) Microstructure Post Processing of Forging

13. Discrete Lattice: Cellular Automata, (50x50) Square Horizontal and Vertical BCs: Periodic, Wrap Around Grain boundary and Neighborhood: Grain Boundaries coupled to material flow: No Neighbor Hood: Moore’s Neighborhood, R=1 Dislocation Density Calculation Constants ε0=1 Q=416,780 h0=0.00075 r0=2000 K=6000 m=0.0055 Recrystallization Phenomena: DRX Nucleation Conditions for new grains: Function of a threshold dislocation density Nucleation Conditions for new grains: n/a Grain growth phenomena selection and material constants: Grain Growth: Function of GB migration velocity, constant=1 Flow Stress phenomena selection and material constants: n/a ρi = 1 D=0.1 δ=0.1 Initial MS Input: Generate GB and orientations separately: System generate, average GS = 0 Generate GB Orientations: System generate, random Initial dislocation density ρi=0.01 Microstructure Post Processing Settings

14. P21 P18 P6 Microstructure – Core Locations Grain Orientation,Step 1

15. P21 P18 P6 Microstructure – Core Locations Grain Orientation,Step 43

16. P21 P18 P6 Microstructure – Core Locations Grain Size Histogram,Step 1 Point 6: Average GS=9.70 Point 18: Average GS=9.50 Point 21: Average GS=9.76

17. Microstructure – Core Locations Grain Size Histogram,Step 43 Point 6: Average GS=2.05 Point 18: Average GS=1.89 P21 P18 P6 Point 21: Average GS=2.02

18. P21 P18 P6 Microstructure – Core Locations Grain Boundary Misorientation,Step 1

19. P21 P18 P6 Microstructure – Core Locations Grain Boundary Misorientation,Step 43

20. P14 P16 P15 Microstructure – Tooth Locations Grain Orientation,Step 1

21. P14 P16 P15 Microstructure – Tooth Locations Grain Orientation,Step 43

22. Microstructure – Tooth Locations Grain Size Histogram,Step 1 Point 14: Average GS=9.80 Point 15: Average GS=9.59 P14 P16 P15 Point 16: Average GS=9.81

23. Microstructure – Tooth Locations Grain Size Histogram,Step 43 Point 14: Average GS=1.97 Point 15: Average GS=2.07 P14 P16 P15 Point 16: Average GS=1.91

24. Gear Core Grain Size Changes Point 6: 9.70  2.05 Point 18: 9.50  1.89 Point 21: 9.76  2.02 Gear Tooth Grain Size Changes Point 14: 9.80  1.97 Point 15: 9.59  2.07 Point 16: 9.81  1.91 Decreased Grain Size in Core and Tooth Areas (from Step 1 to 43)

25. Cooling Simulation Setup and Results

26. Main Axisymmetric Geometry Modes Deformation Phase Transformation Mesh #Structured Surface Mesh Layers=2 Layer Thicknesses: 1=.005, 2=.01 Workpiece Initialization Don’t Initialize Temperature Phase Volume Fraction (Austenite)=1 Temperature = 2200°F Step Settings Starting Step = -44 (last step of forging) (Max) Number of Steps = 1000 1 Step = 5°F Min Temp Time Step = 5 sec Max Temp Time Step = 30 sec Duration = 5400 sec Air Cool Simulation Settings Pyrowear 53 • Process Conditions • Heat Transfer • Environment Temperature = 68F • Coefficient=5.787e-06But/sec/in2F • Boundary Conditions • Outside of Gear, all surfaces • Media Type = Air • Environment Temperature = 68°F • Convection Coefficient = 5.787e-06 But/sec/in2F • Symmetrical planes in vertical and horizontal directions • Material • Pyrowear, Heat Treat *Heat Treat Wizard used for Model Setup

27. Pyrowear 53 Temperature (°F) Time Step #5 Time = 25 seconds Step #250 Time = ½ hour Step #425 Time = 1 ½ hrs

28. ~1260°F Step #155 Time = 13 minutes Pyrowear 53 Temperature (°F)

29. Pyrowear 53 Phase Transformation, Time=0

30. Pyrowear 53 Phase TransformationTime=1000 seconds Temperature Tempered Ferrite + Cementite Austenite Martensite

31. Pyrowear 53 Phase TransformationTime=1800 seconds Temperature Austenite Tempered Ferrite + Cementite Martensite

32. Tempered Martensite Tempered Ferrite + Cementite Ferrite Martensite Pyrowear 53 Phase TransformationTime=5400 seconds Temperature

33. Pyrowear HardnessStep 425, Time = 5400 seconds

34. Pyrowear 53 TTT Diagram

35. Pyrowear 53 Air Cool: Time Vs Temperature