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Economics of Advanced Welding Techniques. March 28, 2013. Stephen Levesque Director, EWI Nuclear Fabrication Center Email: [email protected] Office: 614-688-5183 Mobile: 614-284-5426. Nuclear Fabrication Consortium. - PowerPoint PPT Presentation
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March 28, 2013
Economics of Advanced Welding Techniques
Stephen LevesqueDirector, EWI Nuclear Fabrication CenterEmail: [email protected] Office: 614-688-5183Mobile: 614-284-5426
Nuclear Fabrication Consortium Some information in this presentation was based
upon research funded by the US Department of Energy through the Nuclear Fabrication Consortium (operated by EWI)
The Nuclear Fabrication Consortium (NFC) was established to independently develop fabrication approaches and data that support the re-establishment of a vibrant US nuclear industry
Overview Laser Welding
─ Process description (Laser and Hybrid Laser Technologies)─ Potential applications─ Cost benefit
Friction Stir Welding─ Process description─ Potential applications─ Cost benefit
Cladding Technologies─ Comparison of various technologies
Tandem GMAW (bonus)
Laser Welding
Laser Background Solid-state laser technology is rapidly
advancing ─ Output powers are continuously increasing─ Price per kilowatt is dropping
(~$750K for 20-kW)─ Improved portability and electrical efficiency─ Improved beam quality – fiber deliverable
Two laser technologies primarily responsible─ Fiber Laser (IPG Photonics)─ Disk Laser (Trumpf)
ROI for laser processing is becoming more attractive─ Cost/watt, cycle time, penetration, distortion
Advantages and Challenges The main advantages of laser
processing include:─ High productivity─ Low heat input─ Minimal distortion
Some challenges include:─ Critical joint preparation due to
limited gap bridging─ Increased capital cost compared to
traditional arc-welding equipment
0.005-in. gap 0.010-in. gap 0.015-in. gap
General Terminology Autogenous Laser Welding
Shielding gas
Laser Beam
Laser-Induced Vapor Plume
Laser Keyhole
or Vapor Cavity
Liquid Weld Pool
Solidified Weld Metal
General Terminology Hybrid Laser-Arc Welding (Hybrid Welding)
─ The combination of two welding processes in the same weld pool
─ Most often GMAW and Laser Welding
Laser Beam
GMAW Torch
“Arc-Leading” HLAW“Laser-Leading” HLAW
Hybrid Terminology The HLAW process can be used in two orientations:
High-level cost model built by EWI Assumes 1 min. of arc time for GTAW and 2 sec. of laser
time per tube Varied process efficiency to evaluate the ROI
0 20000 40000 60000 80000 100000$0
$50,000
$100,000
$150,000
$200,000
$250,000
$300,000
$350,000
$400,000
$450,000
$500,000
$550,000
2kW Laser @ 50%
Manual GTAW @ 50%
Orbital GTAW @ 75%
Robotic GTAW @ 80%
Number of Tubes
Estim
ated
Cos
t
Laser Tube Sheet Welding
Laser Tube Sheet Welding
Containment Welding Hybrid Laser-GMAW welding vs. Tandem GMAW vs.
Submerged Arc Welding
Productivity For one weldment X long
"10" 50-in Parts
"10" 200-in Parts
Hours
SAW 11 27
Tandem 8 18
HLAW 15 16
Includes setup time and weld time
Cost Comparison
"10" 60-in Parts
"10" 200-in Parts
Dollars
SAW $48k $124k
Tandem $38k $84k
HLAW $69k $72k
For one weldment X long
Equipment Cost
SAW $55k
Tandem $150k
HLAW $950k
Includes setup time/weld time
(@$75/hr) and filler metal cost
Combined Comparison Data
200-in
Other Benefits Peak Temperature Models showing reduction in heat
input
SAW
GMAW-T
HLAW
Distortion and Residual StressSAW Tandem HLAW
Friction Stir Welding
Friction Stir Welding Invented by TWI in 1991
─ Wayne Thomas Solid-state joining process
─ No bulk melting of the substrate Capable of joining
─ Aluminum, Magnesium, Copper, Steel, Titanium, Nickel, many more
Non-consumable tool rotates and traverses along a joint
─ Combination of frictional heating and strain causes dynamic recrystallization
─ Adiabatic heating Creates a very fine grain microstructure
─ Low distortion─ Excellent weld properties
Friction Stir Welding Variables Essential FSW variables
─ Vertical (Forge) force, Fz
─ RPM, ─ Travel (Traverse) speed, Vf
Process forces─ Travel (Traverse) force, Fx
─ Cross (Transverse) force, Fy
─ Vertical (Forge) force, Fz
Fx Fy
FzVf
Fx Fy
FzVf
Fx Fy
FzVf
Fx Fy
FzVf
Fx Fy
FzVf
Fx Fy
FzVf
Fx Fy
FzVf
Fx Fy
FzVf
Fx Fy
FzVf
Fx Fy
FzVf
FxFy
FzVf
Fx
Fy
FzVf
Ref: Arbegast, William J., "Week 2 Friction Stir Joining: Process Optimization." (2003).
Friction Stir Welding
Local Clamp
FSW Tool
Main Spindle
Fixturing
FSW Economics FSW of Aluminum
─ 15% reduction in man-hour per ton rate in aluminum panel fabrication – Hydro Aluminum
─ Total fabrication savings of 10% in shipbuilding - Fjellstrand─ 60% cost savings on Delta II and IV rockets – Boeing─ 400% improvement in cycle time for fabricating 25mm thick
plates – General Dynamics Land Systems FSW of Steel Pipeline
─ Estimated cost savings ─ Onshore construction, 7%─ Offshore construction (J-Lay), 25%
- Kallee, S. W. (2010). Industrial Applications of Friction Stir Welding. In D. Lohwasser, & Z. Chen, Friction Stir Welding From Basics to Applications (pp. 118-163). Boca Raton: CRC Press.- Kumar, A., Fairchild, D. P., Macia, M., Anderson, T. D., Jin, H. W., Ayer, R., . . . Mueller, R. R. (2011). Evaluation of Economic Incentives and Weld Properties for Welding Steel Pipelines Using Friction Stir Welding.Proceedings of the Twenty-first (2011) INternational Offshore and Polar Engineering Conference (pp. 460-467). Maui: ISOPE.
FSW of Steel Cost Model Assumptions
─ Plain carbon steel─ Simple butt joint configuration─ Use of EWI DuraStir™ tools─ Machine and fixturing purpose built for assumed application─ Range of thicknesses
─ 3, 6, 9, 12, 16, 19 mm─ Broken down in terms of cost/meter based upon weld length
achievable each month
FSW Cost SummaryCost Summary
Thickness 3.00 (mm) 6.00 (mm) 9.00 (mm) 12.00 (mm) 16.00 (mm) 19.00 (mm)
Production Costs: $246.31/m $307.24/m $373.45/m $444.94/m $531.46/m $613.51/mFixed Costs: $18.12/m $21.44/m $27.94/m $28.31/m $40.52/m $53.20/mVariable Costs: $36.46/m $41.32/m $62.65/m $83.29/m $127.46/m $306.23/m Total Cost Per Meter: $300.88/m $370.00/m $464.05/m $556.55/m $699.44/m $972.94/m
Cladding
Introduction Many process options exist for weld cladding
and hardfacing A number of factors should be considered when
selecting a process: ─ Desired deposition rate─ Required dilution level─ Welding position─ Component size/geometry─ Method of application
─ Manual/semi-automatic─ Mechanized─ Automated
─ Welder/operator skill─ Alloy/material to be
deposited─ Equipment cost
Available Processes for Surfacing Include Thermal spray Resistance cladding Laser cladding Gas tungsten arc welding (GTAW) Plasma arc welding (PAW) Gas metal arc welding (GMAW) Submerged arc welding (SAW)
─ Single and multi-wire SAW─ Submerged arc strip cladding─ Electroslag strip cladding
Explosion welding
Resistance Cladding Uses Simple off the shelf sheet material and may use
interlayers to make a fusion type weld between CRA and Pipe
Can make the clad weld in one pass Uses sheet metal consumables which are much
lower cost than wire consumables Post weld surface finish should meet customer
requirements No dilution of base metal into CRA surface
Resistance Cladding
Current Cladding Techiques Explosive Welding $$$$
─ Requires post cladding longitudinal seam weld which impacts fatigue
Roll Bonding ─ Requires post clad longitudinal seam weld
GMAW / GTAW / SAW welding─ Processing time intensive with inspectability issues
Liner Expansion (lowest cost)─ Risk of liner buckling is concerning to customers during
installation or dynamic lines
Resistance Cladding Cost comparison
CRA Piping
Expanded Liner Pipe
Roll Bonded Pipe
RSEW Pipe
0 20 40 60 80 100 120
Normalized Price Per Unit
Tandem GMAW Bonus Material
Why Use Tandem GMAW? Improve Productivity and
Quality─ Increased deposition rates─ Faster travel speeds─ Maintain or improve overall
weld quality, gap filling capability
Deposition rate (lbs/hr)
Image courtesy of Lincoln Electric
Example 5.25-in.-thick test joint 0.5-in.wide groove 2° included angle Travel speed: 15 ipm Heat input: 46 kJ/in. Single bead per layer 27 passes required to fill
4.5 in. Fill height per pass ≈ 0.17 in. Clean UT results