High-Performance GMAW

1. High-Performance GMAW Paul Blomquist Applied Thermal Sciences, Inc.

2. NSRP Welding Technology Panel Project“High Performance GMAW” Awarded late February, 2011 Project Team: Applied Thermal Sciences, Inc. Vigor (Todd-Pacific) Shipyards HII - Ingalls and HII - Newport News Concurrent Technologies Corp. Scheduled Completion: 2/28/2012

3. The Hymn of Breaking StrainRudyard Kipling - 1935 The careful text-books measure (Let all who build beware!) The load, the shock, the pressure Material can bear. So, when the buckled girder Lets down the grinding span, The blame of loss, or murder, Is laid upon the man. Not on the Stuff - the Man! "Galloping Gertie" Collapses November 7, 1940 http://www.wsdot.wa.gov/tnbhistory/Connections/connections3.htm

4. Two Short Statements about Progress “Form Follows Function” - Louis Sullivan -1896 “The Tall Office Building Artistically Considered” “Form Follows Failure” - Henry Petroski -1994

5. Outline • Historical Perspective • About ATS • NSRP Panel Project Technical Approach • Goals – consensus as to shipyard needs • Percentage of mechanized v. semi-auto • Migration from semi-auto to mechanized/auto • “Benchmarking” • What does the market offer? • Many new items – how do they compare? • Interesting R&D, especially foreign • Potential of modification to existing equipment • Challenges for implementation • Q&A

6. Historical Perspective Bare Rods & Covered Electrodes SAW & GMAW Short-Arc & (Marginal) Pulse FCAW –Widespread Cost Reductions Inverters & Better Inverters Combined & Hybrid Processes Differentiation & More Improvement Truly an exciting time in welding!

7. About ATS • R&D & Limited Manufacturing • Conventional & Laser-Based Welding • 20,000 ft2 Manufacturing Facility • Two 10kW Lasers: Gantry & Robotic Integration • First in US to Qualify HLAW for Primary Hull Apps • Manufacturing Products for DDG-1000 (Outfitting) • Internal Combustion Engine Development • Scram-jet, Rocket & Missile Development

8. AWS Conference on Welding in Shipbuilding – Seattle, WA – May 11, 2011 Advanced HLAW System Approach Basic HLAW Weld Parameters Laser GMAW Motion System Gas Flow Control Parameters Gap response Mismatch response Sensor Input Laser feedback GMAW feedback Joint Data Motion feedback On-the-fly inspection User Defined Process Limits Gap/Mismatch GMAW Voltage/Current Weld Speed Laser Power Post Weld Inspection Adaptive Process Control and Weld Quality Assurance

9. ATS HLAW Processing Facilities 20,000 Sq ft Production Space HLAW Gantry (2005) ESAB/ATS CNC Gantry 16ft (5m) x 50ft (15m) modular weld space IPG 10kW fiber laser

10. ATS HLAW Processing Facilities Robotic Workcell (2008) ABB IRB4400 (2m) Trumpf TruDisk 10003 (10kW)

11. HLAW Fillet-Reinforced Tee Welding

12. Objective: • Develop HLAW process for structural shapes • Qualify to NAVSEA & ABS NVR • First US Qualification of HLAW process • for Primary Hull Structure US Shipbuilding - HSLA65/HSLA 80

13. Orthotropic Bridge Decks Objective: Demonstrate process feasibility Fabricate specimens for fatigue testing

14. Metallic Sandwich Panel Design / Welding

15. Sub-Scale/Full Scale Testing

16. NSRP Panel Project Technical Approach • HLAW Performance: Breakthrough • Recent progress with HLAW has shown ~10X improvement • Capital Cost: “Break-bank” • Hybrid systems can cost ~20X – and restructuring may be needed • Lower-Cost Hybrid Processes – HPAW; Zhang; etc. • Recent Progress with GMAW power supplies and process development shows major improvements • Find a “sweet spot” of increased performance at acceptable cost • Determine path to implementation • For existing equipment, determine why implementation has not occurred

17. The Promise of Higher Penetration Convert the double fillet weld to a fillet-reinforced tee weld

18. Lower-Cost Hybrid Processes http://cgi.ebay.com/PHILLIPS-PLASMA-MIG-WELDING-POWER-SUPPLY-/350329713149?pt=LH_DefaultDomain_0&hash=item51914731fd http://www.nsrp.org/Ship_Production_Panels/Welding_Technology/downloads/080508_Modified_GMAW_System.pdf

19. Recent Progress with GMAW • New Equipment • All the makers have something new or recent • Many on display here • Some soon to be released • Is there a reason not to buy inverters?

20. Interesting Variants – Single GMAW Source I2R Heating (long stick-out) • Long history with SAW • Short life for GMAW? • 25% increase in WFS at same heat input • 2X Tip life (yes, doubled) – but • 10X Tip Cost! http://www.migfast.com/downloads/MIGfast_AWJ_article.pdf

21. Interesting Variants – Single GMAW Source “HI-Pen” • Zdeněk Hudec, Technical University of Liberic, CZ • Modify GMAW inverter parameters • Investigating “short-spray” region ~6V below standard spray • Substantially higher penetration/speed • Potential for application to existing equipment Spray Short-spray

22. HI-Pen -Results • Substantial increase in penetration • Reduce weld volume • Reduced filler metal usage • Potentially reduced fume levels • Higher dilution with base metal • Potentially higher weld speed

23. Challenges • Are we happy with what we’re seeing coming to market at this time? If not: • What do we need? • Better penetration? – good for fillets? • Does this imply volumetric NDT? • Lower heat input means lower distortion • Always true? HAZ issues? • Higher dep rate at lower heat input – good for semi-auto? • Higher penetration - good for semi-auto? • What is needed to assure shipyard implementation? • Training • Maintenance and parts support • Other obstacles to implementation

24. Questions? Applied Thermal Sciences, Inc. Sanford, Maine