simulation of 3d metal forming pocesses of axi-symmetric products …€¦ · simulation of 3d...
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SKF Engineering & Research Centre
Simulation of 3D metal forming pocesses of axi-symmetric
products
FENET MeetingNovember 13, 2001
Wiesbaden, GermanyGerrit-Jan Dop
SKF Engineering & Research Centre
3D process to manufacture axi-symmetric product
• axi-symmetric billet• fully 3D process• axi-symmetric product
• Orbital Forming• Ring Rolling
SKF Engineering & Research Centre
OVAKO's Radial/Axial Ring Mill #9
• manufacturer : Wagner (Germany)• axial force 125 ton• radial force 125 ton• data-logger feature (99 channels)• speeds and forces are calculated
based on billet and final geometry, using the RollTech program
• both king roll and cones are driven (mandrel motor is not installed)
SKF Engineering & Research Centre
OVAKO's open die hot Ring Rolling Processes
HOT RING ROLLING
ODWidth [mm]
Mass[kg]
Capacity[rings/h]
machining allowance
tolerance[mm]
RM 7;die rolling mill
130~27030~90
1~7 400~820 3.0 1.0
RM 8;radial rolling mill
150~38040~130
5~19 300~500 4.5~7.0 1.7~3.0
RM 4;radial-axial rolling mill
230~65075~230
15~70 40~70 5.0~8.0 2.0~3.6
RM 9;radial-axial rolling mill
300~300050~530
50~2500 10.0~44.0 4.0~21.0
COLD RING ROLLING
80 0.0301
SKF Engineering & Research Centre
Hot Ring Rolling• 1150 deg. cent.• +low process forces (comp. to cold/warm)• -inclusions originating from ingot not broken
up• -high costs in re-heating• -big tolerances and allowances• -problems with porosity (porosity increases if
hydrostatic pressure becomes negative during the process)
• -forming of laps • -geometrical defects
SKF Engineering & Research Centre
Cold Ring Rolling• preferred solution • +less waste• +no costs in re-heating• +finer micro-structure• +inclusions more broken-up• +better fatigue properties• - higher process forces• -limited product size• -cracks on OD• -problems with filling of die
SKF Engineering & Research Centre
Process defects
Porosity during blankingPorosity during blanking
Geometric defectsGeometric defects
SKF Engineering & Research Centre
Warm Ring Rolling
• <730 deg. centigrade• lower process forces than in cold RR• used for medium sized rings• less energy consumed in re-heating
compared to hot RR
SKF Engineering & Research Centre
Why are Ring Rolling problems so difficult to solve
• many contact changes (40 revs)• friction driven process• many small increments of plastic work• (almost) rigid body mode at start of
process• small contact zone vs. large workpiece• fully coupled thermo-mechanical
problem
SKF Engineering & Research Centre
FEA codes that were considered
• MARC & MARC/Autoforge• DEFORM• Forge3• ABAQUS/Standard• ABAQUS/Explicit
SKF Engineering & Research Centre
Selection criteria
• able to simulate one case in less than 2 days on $50.000 hardware
• good GUI, preferably in terms of process design engineer
• stable and user friendly code• open code ; experts and R&D people must be
able to add to the code• preferably one code for all metal forming
applications• vendor with good reputation and world wide
support network
SKF Engineering & Research Centre
ABAQUS ANIMATION FILES
• radial-axial ring rolling : temperatures
• radial-axial ring rolling : Equivalent plastic strain
• radial ring rolling : temperatures• radial ring rolling : Equivalent plastic
strain
SKF Engineering & Research Centre
Shape of the cross section of the formed ring (2)
Theoretical rolled dimension [mm]
Abaqus/Explicit dimension [mm]
OD 161.3 159.24
ID 126.0 124.8
Draceway 133.7 132.5
Width 38.3 38.28
SKF Engineering & Research Centre
ComparisonCPU Time GUI
Gui in process terms
Stable and user friendly
open code world wide support
MARC/ Autoforge
45 days yes --+
++ ++
Deform * yes n.a. n.a. +
Forge/3 15 days yes ++++
+ +
ABAQUS/Standard
45 days can be custom.
+++
+ ++
ABAQUS/Explicit
2 days can be custom.
+++
+ ++
SKF Engineering & Research Centre
Conclusionsboth Forge/3 and ABAQUS/Explicit are capable of simulating the Ring Rolling process,it is a matter of "time invested in setting up the modelling" that determines the quality of the result ( to a large extent ),the implicit FEA codes ( MARC/Autoforge, Forge2/3, DEFORM, ABAQUS/Standard) take too long to solve the Ring Rolling simulation, even on very fast hardware,ABAQUS/Explicit is the only code that was investigated that yields results that are acceptable at first sight and within computational times that allow for case studies and optimisationby means of analysis,Expecting analysis with a precision of well below 0.5 [mm] (on the diameter) for rings with a diameter of 150 [mm] seems unrealistic,However the influence on the final product of changes in geometry and process parameters can be studied efficiently. These semi qualitative answers can be used to optimise the product and process.
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