DEFORM Simulation Results 2D Hot Forging and Air Cool of Gear Tooth Geometry Holly Quinn 12/04/2010

DEFORM Model 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 Initial Contact Pairs: 1. WP to Bottom Die 2.WP to Top Die Top Die Bottom Die Workpiece

Forging Simulation Setup and Results

Forging Simulation Settings 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 for Velocity 0.01 for Force Process Conditions –Heat Transfer Environment Temperature = 68F Convection Coefficient=5.787e-6 But/sec/in 2 F –Diffusion Environment Atom Content = 1.69% atm Reaction rate coefficient = 1e-5 in/sec Advanced –Contact Error Difference Tolerations =

Materials Top Die Workpiece Bottom Die

Temperature, Final Time step

Displacement Flash

Effective Stress

Effective Strain

Effective Strain Rate

FlowNet Tracking of Material Flow

Microstructure Post Processing of Forging 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 Settings 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 –ε 0 =1Q=416,780h 0 = –r 0 =2000K=6000m= 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 –ρ i = 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 ρ i =0.01

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

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

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

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

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

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

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

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

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

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

Decreased Grain Size in Core and Tooth Areas (from Step 1 to 43) 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

Cooling Simulation Setup and Results

Air Cool Simulation Settings Pyrowear 53 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 Process Conditions –Heat Transfer Environment Temperature = 68F Coefficient= 5.787e-06 But/sec/in 2 F Boundary Conditions –Outside of Gear, all surfaces –Media Type = Air –Environment Temperature = 68°F –Convection Coefficient = 5.787e-06 But/sec/in 2 F –Symmetrical planes in vertical and horizontal directions Material –Pyrowear, Heat Treat *Heat Treat Wizard used for Model Setup

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

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

Pyrowear 53 Phase Transformation, Time=0

Pyrowear 53 Phase Transformation Time=1000 seconds Austenite Martensite Tempered Ferrite + Cementite Temperature

Pyrowear 53 Phase Transformation Time=1800 seconds Austenite Martensite Tempered Ferrite + Cementite Temperature

Pyrowear 53 Phase Transformation Time=5400 seconds Ferrite Martensite Tempered Ferrite + Cementite Tempered Martensite Temperature

Pyrowear Hardness Step 425, Time = 5400 seconds

Pyrowear 53 TTT Diagram

Pyrowear 53 Air Cool: Time Vs Temperature