High-Performance GMAW

AWS Conference on Welding in Shipbuilding – Seattle, WA – May 11, 2011

High-Performance GMAW

Paul BlomquistApplied Thermal Sciences, Inc.


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NSRP Welding Technology Panel Project“High Performance GMAW”

Awarded late February, 2011

Project Team:Applied Thermal Sciences, Inc.Vigor (Todd-Pacific) ShipyardsHII - Ingalls and HII - Newport NewsConcurrent Technologies Corp.

Scheduled Completion: 2/28/2012


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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 girderLets 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


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“Form Follows Failure”- Henry Petroski -1994

“Form Follows Function”- Louis Sullivan -1896

“The Tall Office Building Artistically Considered”

Two Short Statements about Progress

http://www.amazon.com/gp/reader/0679740392/ref=sib_dp_pt#reader-link


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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


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Historical Perspective

Bare Rods & Covered ElectrodesSAW & GMAW Short-Arc & (Marginal) PulseFCAW –Widespread Cost ReductionsInverters & Better InvertersCombined & Hybrid ProcessesDifferentiation & More Improvement

Truly an exciting time in welding!


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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


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Advanced HLAW System Approach

Sensor Input Laser feedback GMAW feedback Joint Data Motion feedback On-the-fly inspection

Control Parameters Gap response Mismatch response

User Defined Process Limits Gap/Mismatch GMAW Voltage/Current Weld Speed Laser Power Post Weld Inspection

Basic HLAW Weld Parameters Laser GMAW Motion System Gas Flow

Adaptive Process Control and Weld Quality Assurance



ATS HLAW Processing Facilities

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20,000 Sq ft Production SpaceHLAW Gantry (2005) ESAB/ATS CNC Gantry

16ft (5m) x 50ft (15m) modular weld space IPG 10kW fiber laser


ATS HLAW Processing Facilities

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Robotic Workcell (2008) ABB IRB4400 (2m) Trumpf TruDisk 10003 (10kW)


HLAW Fillet-Reinforced Tee WeldingProject Application Material Development

Objective Status

ONR HSLA65

Structural Tee Beams HSLA65 Process/Product

Qualification

Qualification approvedCustomer has purchased machine

ONR HSLA80

Structural Tee Beams HSLA80 Process

Qualification Qualification approved

LASCOR Lap Welds AL2003 Duplex SS

High Productivity / Low Heat input

Qualified

NGRTC Lap Welds 90XF High Productivity Complete

PSI-FHwA

Orthotropic Bridge Decks

A572 Gr50

100% Penetration – single side

Test articles submitted for fatigue testing

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US Shipbuilding - HSLA65/HSLA 80

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Thickness 0.188, 0.250 ,0.313, 0.375

Travel Speed 70-115 ipm

Laser Power 5.5-6.5 kW

Objective: •Develop HLAW process for structural shapes •Qualify to NAVSEA & ABS NVR•First US Qualification of HLAW process

for Primary Hull Structure


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Orthotropic Bridge Decks

Thickness 0.313 (8mm) A572

Travel Speed 50 ipm

Laser Power 8.5kW

Special Full Pen – single side

Objective: Demonstrate process feasibility Fabricate specimens for fatigue testing

http://bigfoot/engineering/HLAW/Weld%20Images/3497%207x%200%20dec%20OH%20T%20PSI-FHWA%200312%20Web.jpg


Metallic Sandwich Panel Design / Welding

Project Application Material Development Objective

Status

ONR LASCOR Duplex Stainless

Process FeasibilityProduct Testing

Feasibility confirmedTesting completed

DDG1000 Duplex Stainless

Lightweight structure In Production

NGRTC Crash protection

90XF Panel fabrication Completed

Commercial Trailer Deck ATI2003 Lightweight/Modular Prototype deliveredCommercial Mezzanine

FloorsCS High Productivity Feasibility confirmed

Awaiting Application

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Sub-Scale/Full Scale Testing

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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


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The Promise of Higher Penetration

Double Fillet Weld Hi-Penetration Weld0.375-in fillet Full penetration with

0.125-in fillet reinforcement

0.578 lb/ft 0.144 lb/ft≈34,700 lb/ship ≈8600 lb/ship

Convert the double fillet weld to a fillet-reinforced tee weld


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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


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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?


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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


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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


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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


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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


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Applied Thermal Sciences, Inc.Sanford, Maine

Questions?

High-Performance GMAW

Documents

shipbuilding seattle

fiber laser aws conference

progressaws conference

hlaw filletreinf

modular weld space ipg

project team

auto migration

consideredtwo short