Development of Hybrid Rapid Infrared Heat Treating Furnace for Aluminum Forgings

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Development of Hybrid Rapid Infrared Heat
Treating Furnace for Aluminum Forgings

• Rob Mayer1, Puja B. Kadolkar2, Frank Kraft3,
  Vamadevan Gowreesan3, Devon Poling3, Jay S.
  Gunasekera3, Percy Gros4, George Mochnal5, and
  Craig A. Blue2
• 1The Queen City Forging Company, Cincinnati OH
• 2Oak Ridge National Laboratory, Oak Ridge TN
• 3Ohio University, Athens OH
• 4Edison Materials Technology Center, Dayton
  OH5Forging Industry Association, Cleveland OH

26th Forging Industry Technical Conference
November 7-9, 2005 Crowne Plaza Chicago
OHare Rosemont, IL
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Acknowledgements

• Project Funded by the Cooperative Research and
  Development Agreement (CRADA) ORNL
• Project Funded by US DOE, Office of Energy
  Efficiency and Renewable Energy, Industrial
  Technologies Program, Supporting Industries,
  Industries Materials of the Future, and Aluminum
• Project Funded by Edison Materials Technology
  Center
• Research Supported by
• Komtek
• Northeastern University
• Infrared Heating Technologies
• Forging Industry Association
• Ohio University

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Outline

• Infrared Technology
• Rapid Infrared Pre-heating of Forging Dies
• Rapid Infrared heating of Aluminum billets prior
  to Forging
• Field testing of a full-scale billet heating
  production setup at Queen City Forging
• Rapid Infrared heating for Heat Treatment of
  Aluminum Forgings
• Optimization of Heat treating Parameters
• Development of a full-scale infrared heat
  treatment facility at Queen City Forging Company
• Conclusions

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Infrared Technology

• Infrared heating provides a clean, non-contact
  heating technique
• The tungsten halogen heating element is heated in
  excess of 4000F resulting in high thermal fluxes
• Radiated energy heat flux is nearly ten times of
  a gas-fired infrared system, heating rates of
  200-300?C/s are possible
• Convert electrical into radiant energy in excess
  of 90.
• Low thermal mass provides instantaneous starting
  and stopping allowing precise control over
  temperature and output.
• Uniform deposition of radiant energy.

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Infrared Pre-heating of Forging Dies

• Increase in Productivity
• Reduced heating times
• Increase in die life
• Uniform temperature
• Better lubrication, lesser sticking problems
• Energy savings
• Efficient heating and shorter wait times in
  between forging

Insert Die Heater
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Insert Die Heaters Currently Installed

• American Tool
• American Axle
• Ameriforge
• Alcoa
• Eaton
• Finkl Sons
• Klein Tool

• Komtek
• Milwaukee Forge
• Queen City Forging Company
• TRW
• Turn Key Forge
• United Defense

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Rapid Infrared Heating of Aluminum Billets
Laboratory based batch-type infrared furnace used
to identify rapid heating rates
2.25 inch-diameter, 6-inch-long AA 2618 billets
were heated in 16 mins (Conventional hold times
to preheat loads is about 4 hrs)
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Rapid Infrared For Heat Treatment of Al Forgings
Conventionally preheated, forged, conventionally
solution heat-treated and conventionally aged AA
2618 forgings (Controlled)
Rapidly preheated, forged, rapidly solution heat-
treated and conventionally aged AA 2618 forgings
Grain size 40 um
Grain size 27 um
30 Reduction in grain size with rapid preheating
and rapid heat-treatment
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Improvement in Mechanical Properties

• Higher hardness and UTS values were achieved with
  rapidly heated forgings

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Improvement in Mechanical Properties
Stress amplitude vs. number of cycles of T61
treated specimens under tension-tension loading
condition with mean tensile stress at 180 MPa.

• Rapid preheating and rapid solution heat-treating
  produces stronger forgings with two times the
  fatigue life

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Full-scale Production Setup

• Hybrid infrared furnace setup at The Queen City
  Forging Company
• Optimized combination of radiant and convective
  heating
• Continuous belt setup for higher throughputs

Recipient of the prestigious 2004 RD 100 Award
Participants Komtek, Oak Ridge National
Laboratory, The Queen City Forging Company,
Northeastern University, Forging Industry
Association and Infrared Heating Technologies Inc.
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Infrared Applications in Aluminum Forging
Conventionally preheated, forged and
conventionally heat-treated
Rapidly preheated, forged and rapidly
heat-treated
Micrographs showing magnitude of grain refinement
in AA 2014 Looper Drag Link (used in industrial
sewing machines) hammer forged and T4 treated
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Infrared Applications in Aluminum Forging
Conventionally preheated, forged and
conventionally heat-treated
Rapidly preheated, forged and rapidly
heat-treated
Higher magnification micrographs of the middle
section
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Optimization of Heating Treating Parameters

• Laboratory studies being performed at Ohio
  University
• Goal is to optimize the heat treating parameters
• Conserve Energy and Increase Productivity
• Possible Improvement in Materials Properties
• Conductivity and hardness measurements on samples
  in the as-solutionized condition are used to
  indicate the extent of dissolution of solute
  elements during the solution heat treatment
  process
• Conductivity and hardness measurements are
  performed on aged samples to study the age
  hardening effect

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6061 Conductivity (as-solutionized)
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6061 Hardness (as-solutionized)
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6061 T6 Aged (175 C for 8hrs)
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6061 T6 Aged (175 C for 8hrs)
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As-extruded
6061
532 C, 20 s
572 C, 900 s
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7075 solutionized T73 aged (107 for 7 hrs
177
for 9 hrs)
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Development of Full-Scale Heat-Treating Facility
at Queen City Forging Company
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Development of Full-Scale Heat-Treating Facility
at Queen City Forging Company
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Development of Full-Scale Heat-Treating Facility
at Queen City Forging Company
Loading Operation
Quenching Operation
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Development of Full-Scale Heat-Treating Facility
at Queen City Forging Company

• Temperature profile indicating heating of 10
  T/Cs in the heating treating furnace
• Profile shows uniform and controlled heating of
  parts to the required temperature
• Forged parts were heated in 1/2 amount of time as
  compared to conventional HT techniques

1000 deg F
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Summary

• Rapid infrared heating offers a low cost,
  energy-efficient heating methodology for die
  preheating and heating of aluminum billets and
  forgings
• Field testing of the hybrid infrared billet
  preheating system in full-scale production setup
  has demonstrated cost savings up to 40-50
  through reduced energy consumption, increased
  throughput and improved consistency in the
  process and quality of the product.
• Rapidly preheating and rapidly solution
  heat-treating produces stronger forgings with two
  times the fatigue life
• Current efforts involve optimization of the heat
  treating parameters
• Conserve Energy and Increase Productivity
• Improvement In Material Properties
• Development of a full-scale infrared heat
  treating facility is in progress at Queen City
  Forging Company
• Potential national energy savings of 1.8 Trillion
  BTUs/year together with cost savings of 17
  million dollars/year.