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Navy Metalworking Center A ManTech Center of Excellence
Advanced Metalworking Solutions for naval systems that go in harm’s way
Distribution Statement A: Approved for public release; distribution is unlimited.This material is submitted with the understanding that right of reproduction for governmental purposes is reserved for the Office of Naval Research, Arlington, Virginia 22203-1995.
Automated Weld Facing Tools Modified to Perform Back
GougingBruce D. Horn and Timothy G. Freidhoff
NMC/CTC
American Welding Society New Welding Technologies
Conference June 15-16 2010, Ft. Lauderdale, FL
Outline• Integrated Project Team • Problem and Solution• Implementation Results and Benefits• Conclusions and Movie• Questions
Manual Hand Grinding (Photo courtesy of NGSB-GC)
NMC Weld Shaver Concept
Project Outcome, Commercially Available Tool
by PushCorp, Inc.
Integrated Project Team
• Bath Iron Works (BIW): Technical contributor and end user
• General Dynamics Electric Boat (GDEB): Technical contributor
• Naval Surface Warfare Center - Carderock Division (NSWCCD): Navy technical advisor
• Navy Metalworking Center (NMC): Project management and technical lead
• Northrop Grumman Shipbuilding - Gulf Coast (NGSB-GC): Technical contributor and end user
• Office of Naval Research (ONR): Project funding and support
• PMS 500 DDG 1000 Program Office: Stakeholder
• PushCorp, Inc.: Industry partner
Problem• Butt welding of hull and deck panels produces weld
protrusion reinforcement that exceeds DDG 1000 fairness limits
• Hand grinding is currently the only solution to removing weld
• Hand grinding is detrimental to the workforce, resulting in frequent injuries and costly medical expenses
Current weld removal process(Photo courtesy of BIW)
Weld Reinforcement
Weld reinforcement cross section example (i.e., not DDG
1000)
Problem• Hand grinding is slow, further increasing production costs.• There are ≈ 21,000ft of weld reinforcement to remove per hull
Flat orientation ≈ 45%
Vertical and horizontal orientation
≈ 25% each
Overhead orientation ≈ 5%(Photos courtesy of
BIW)
Solution
• Perform assessment at BIW, NGSB-GC and GDEB to understand problems
• Develop prototype tool requirements to address shipyard’s design requirements• Weld width up to 2.25" and height up to 0.3125"• 20 ft/hr weld removal rate versus 3 ft/hr (1" wide weld x
0.3125" high)• Remove 80% of weld height without damaging adjacent panel• Individual component weight approximately 75 lbs or less• Straight and contoured panels (40“ minimum radius, concave
and convex)• Flat, vertical, horizontal and overhead orientations• Tool compliance to plate surface for maximum weld removal.
Solution• Develop concept utilizing a commercially available weld shaver
Flat orientation Horizontal orientation Vertical orientation
Force control
Carriage
Track
Magnets
Weld seam
Safety strap
Slotting cutterWeld shaver
Solution• Validate the track weld shaver concept for shipyard
application
Shaver and track lab test set-up
Lab test results
Weld shaver in production
Solution
Shaver 3.7 HP AC Servo
7075 Aluminum Flex Track 40” R Min
Vertical Axis Slide 2”
Horizontal Slide 2”
Force Control 100 lbs
2 Axis Shaver Rotation
Rare Earth Magnet 220 lbs2 Axis Rotation
Track Quick Connect Cam
WSF Alpha Prototype Tool
Solution• Contract PushCorp, Inc. to develop track weld
shaver concept and commercialize technology
(Photo courtesy of PushCorp, Inc.)
TWS91 commercially available tool from PushCorp, Inc.
BIW Implementation Results
60 ft of hull butt weld removed at approximately
60 ft/hr
Finished hull weld (No hand grinding of weld required)
Photos courtesy of BIW
3 in. wide x 12 ft long weld
(75% labor reduction)
BIW Implementation Results
15 ft of hull butt weld removed at
approximately 125 ft/hr
Overhead orientation
(Photos courtesy of BIW) Ship lifting lug weld removal
NGSB-GC Implementation Results
60 ft of hull weld removed at approximately 240 ft/hr
Finished hull weld
30 ft of weld removed at approximately 60
ft/hr
Photos courtesy NGSB-GC
Track Weld Shaver Benefits
• For panel and lifting lug weld removal, the estimated cost reduction for DDG 1000 is $924,000/hull
• Safer for the workforce • Removes up to 90% of the weld height at a rate up to 240
ft/hr• Automatic removal of weld between 0.375 and 3 inches
wide• Better for the environment• Also being used to remove weld from ship lifting lugs• Applicable for any applications requiring weld removal• The track weld shaver system can be used to perform
multiple operations (shaving, back gouging, sanding, welding and burning)
• Back gouging and sanding operations identified as additional capabilities and having potential for implementation
Track Weld Shaver Benefits
• Track weld shaver technology has potential back gouging use
• Back gouging total estimated cost reduction for DDG 1000, LHA-6, LPD-17 and NSC is $2,626,000
Manual carbon arc back gouging
Mechanical back gouge cross section HSLA-80
plate
(Photos courtesy of NGSB-GC)
Mechanical back gouging HSLA-100 with MIL-120S-1
(Sample courtesy of BIW)
55° “V”84 ft/hr
NGSB-GC
12mm “U”
57 ft/hrBIW
Track Weld Shaver Benefits
Manual sanding
(Photos courtesy of BIW)
Belt sander added to track weld shaver to blend shaved
weld
Finished 3 inch wide weld using belt sander
(Photo courtesy of NGSB-GC)
Conclusions• Track weld shaver technology is safer + faster than
current hand grinding process, which = cost reduction
• Weld shaving estimated cost savings = $2.77M• Back gouging estimated cost savings = $2.63M• Track weld shaver system is currently implemented
at the shipyards to remove weld reinforcement• Track weld shaver technology has the potential to
be used for back gouging, sanding, welding, and burning
• Back gouging needs further refinement and being considered for implementation by shipyards
• Track weld shaver system is now commercially available from PushCorp, Inc.
Contact InformationName Organizati
onTitle Phone Email
John Foster BIWDDG1000 Hull Representative
207-442-3464 [email protected]
Steve Davis BIWLean Process Engineer
207-442-1728 [email protected]
Robert Kirkwood
NGSB-GCDDG1000 Hull Representative
Kevin Roossinck
NGSB-GCSr. Welding Engineer
Tim Freidhoff
NMC/CTC Project Engineer 814-269-2876 [email protected]
Bruce Horn NMC/CTC Project Manager 814-269-2351 [email protected]
Gene Franke
NSWCCDTechnical Advisor
301-227-5571 [email protected]
Rick Zebrowski
PMS 500, Program Office
Stakeholder 301-227-4410 [email protected]
Edwin Erlbacher
PushCorp, Inc. President 972-840-0208 [email protected]
Technology Transfer Movie
