(hlaw) - american welding society · laser + cold wire feed: ... hybrid & tandem laser arc...

June 15, 2010

Hybrid Laser Arc Welding (HLAW)

Paul A. Blomquist Applied Thermal Sciences, Inc.

June 15, 2010 www.appliedthermalsciences.com 2

Acknowledgements

Data included in this presentation has been generated as part of several programs performed by Applied Thermal Sciences, Inc., in some cases while serving as a subcontractor to the Navy Metalworking Center, operated by Concurrent Technologies Corporation (CTC), and/or under various contracts via the Office of Naval Research (ONR) as part of the Navy ManTech Program and other programs, including Small Business Innovative Research (SBIR) programs. Opinions expressed are the author’s and not necessarily those of CTC or ONR.

HybridLaserArcWelding


Acknowledgements‐Continued

The list of partners involved with the development and implementation of this technology alongside ATS is too numerous for complete mention. ATS is particularly indebted to Concurrent Technologies, Inc., Atrium EHS, ESAB North America, Naval Surface Warfare Center, Carderock Division, Naval Research Laboratory, Servo-Robot, Inc., and many others.

HybridLaserArcWelding


•   ATSBackground•   LaserConsiderations•   HybridLaserProcesses:Benefits&Issues•   OpportunitiesforImprovedProductivity

•   MetallurgicalandQualityIssues•   ProcessDevelopmentandQualification•   ApplicationCaseHistories•   DiffusibleHydrogenAspectsofHLAW•   WeldFumeProfilesofHLAW

•   Summary

HybridLaserArcWelding(HLAW)


ATS Background

  EngineeringResearchandDevelopment(R&D)•   Focus–InnovativeEngine,Vehicle&PlatformConcepts

UtilizingAdvancedMaterials&Structures   FederalGovernmentContractor

•   DoD(Navy,MissileDefenseAgency(MDA),Army)•   NASA•   NSF,Others

  PathstoSuccess•   UtilizeFederalR&DFundstoDevelopTechnology

AddressingCustomerNeeds•   IdentifyTechnologyUtilizationinCommercial/Government

Sector•   CommercializeTechnology


ATS Background   Foundedin1989inOrono,Maine

  Incorporatedin1998•   Corporateofficere‐locatedtoSanford,

Maine

  EstablishedLaserFacility,2002 •   Sanford,Maine,15Kft2•   Initiallaser–25kWCO2•   Installed10kWfiberlaser2005•   Installed10kWYAG‐disklaser,2007

  ControlSystemPatentAward,2005   NavseaApproval,HSLA‐65,2007   ContractforduplexSSpanels,2008   NavseaApproval,HSLA‐80,2009   Continuingdevelopmentofprocessesand

equipmentforHLAWapplications


LaserConsiderations

Type of Laser: CO2 – 10,600 nm– delivery via mirrors & lenses YAG & Yb fiber – 1,000 nm delivery via fiber optics

Power of laser: CO2 - ~1 mm penetration per kW @ 1 m/min YAG, Yb, ~1 mm penetration per kW @ 2 m/min

Cost of laser: YAG, Yb ~$75-100K per kW Power buys penetration on thick & speed on thin

Eye Safety: YAG, Yb, everyone wears protection Implementation: optimal when highly automated

Not a “hand-held” tool (some experimental work)


LaserConsiderationsMajor Laser-Based Implementations

  Autogenous LBW:   Largest installed base;

  High-volume, close-tolerance manufacturing

  Laser + Cold Wire Feed:   Provide filler for geometry or properties

  Still requires close-tolerance fit up

  Hybrid & Tandem Laser Arc Welding:

  May combine with GMAW, PAW, GTAW, etc.

  “Hybrid” = laser and arc interact in same weld pool

  “Tandem” = laser & arc separated, two solidification events

  “Tandem” weld speed = speed of slowest process


HybridLaserProcesses:General

SchematicofProcess Graphics:GSI‐SLV

Typicalweldinghead


HybridLaserProcesses:General

Graphics:GSI‐SLV

LaserHighweldingspeedDeeppenetrationLowheatinput

Finemicrostructure

GMAWLow‐costenergysourceManagedheatinputFillermetalprovides:WidergaptoleranceControlofchemistryControlofgeometry

HybridLaserArcWelding(HLAW)Higherprocessstability,higherweldingspeedBettercontrolofcontourplusdeeppenetration

Largerseamvolumewithgoodmetallurgicalproperties


HybridLaserProcesses:Benefits&Issues

  Cost Benefits:   High-speed fabrication >> reduce manufacturing costs

  Highly controllable >> improve quality and consistency

  Value Benefits:   Accurate fabrication: reduce assembly cost

  Reduced distortion, improve schedule

  Flexibility to achieve wide range of applications

  High Speed, High Accuracy :   Significant Opportunity for Downstream Cost Savings


Laser Process Control Objective

•   OptimizetheControlvs.ConstraintEquation–   Partpreparationcostsdecreaseastoleranceincreases–   Weldingcostsincreaseastoleranceincreases–   Objective:processoperateswherecombinedcostisminimized

<Part Tolerance

Pro

cess

Cos

t

Part Preparation Costs

Welding Costs

Total Process Costs


HLAWImplementation ATS/ESABWeldingGantry   ProcessDevelopmentandDemonstration   VerificationofQuality,Productivity,andDimensionalAccuracy   ProcedureQualification   ProductManufacturing



Conventional Fillet‐Reinforced DoubleFilletWeld TeeWeld

Example:0.5”web,doublefillet=0.375”Converttofullpenetration:fillet=T/4=0.125”

ConventionalWeld HLAWeld 0.578 lb/ft

0.144 lb/ft Weld Speed ~24-40 ipm Weld speed ~ 80-100 ipm



•  GMAweldedjointS690QL

•  Numberoflayers:4

•  Materialthickness10mm

•  Weldingspeed0,1..0,3m/min/layer

•  Angulardistortion:high•  DimensionWMandHAZ:wide

•  Laser‐GMA‐hybridweldedjointS690QL



•  Weldingspeed1,5m/min

•  Angulardistortion:low•  DimensionWMandHAZ:narrow

Photos&Data:GSI‐SLV



  Equipment Cost :   Laser ~ 10X conventional source cost

  Less of an issue for “green-field” installations

  Fit-up Tolerances:   Prep and tooling methods are drivers for productivity

  Less of an issue with Hybrid processes, still important

  High Cooling Rate:   High CE alloys may show high hardness in WM & HAZ

  Microstructural evolution of other alloys (e.g. duplex SS)

  Procedure development must anticipate and solve



•   Highlyautomatedprocesscontrols–   Improvedconsistencyinwelddeposits–   Reduceddependencyonindividualvariations

•   Notnecessarilythe“silverbullet”–   Canhaveallthetypicalproblems

•   Highenergydensityprocess–   Canhavesomenewproblems

•   “Keyholecollapse”–keyholeinstabilities•   Theseproblemscanbesolved

–   NAVSEA&ABSapprovalsforHLAWinUS

–   Increasingnumberofapplicationsworldwide



•   Primaryconcern:highcoolingrate•   C‐Mnsteels~</=50‐70ksiyield

•   A‐36,DH‐36,HSLA‐65allseemtobenefit•   Tensiles,CVN’simprove;hardnessmanageable

•   Q&Tsteels~=/>80ksi•   HY‐80&100reactpredictably•   Tensiles,Hardnessincrease;CVN’sconsistentlylow•   Needpreheatforcontrolofcoolingrate

•   Otheralloys•   Microstructuralevolutionmaybetime‐dependant•   E.G.,DuplexStainlessSteels–fastcoolingfavorsferrite•   Canaccommodatewithcoolingratecontrol•   Canaccommodatewithfillermetalchemistry



Weldingof2‐inchthickmaterials

Achievedintwodevelopmentprojects:•   USA1999–PrecisionLaserMachining2”structuralsteel

•   Lowpower(1.8kW),highbrightness“lab”laser,slowtravelspeed

•   AchievedinIPGLab,Germany–   2007–Two20kWfiberlasers,simultaneous2‐sideweld

•   Highpower(40kW),industriallaser,mediumtravelspeed

IPGPhoto


ApplicationCaseHistory#1

HydroTestTankReducingFlange

Problem

NeedforreducingflangeFourasymmetricchannelsEachchannel=11’longTraditionalwelding:quoteexcessiveConcernsofweldingdistortionDesignforconventionalwelding >0.250”machiningallowanceExtrawelding–evenmoredistortionExtensivemachining

Graphic:UniversityofMaine



Hydro Test Tank Reducing Flange

Solution

SwitchtoA‐36“U‐M”bars,0.5”&0.75”Machiningallowance–0.062Squarebutt/cornerjointsMinimalprep:as‐received+gritblastMinimalfilletreinforcementLowheatinputLBWMinimalmachiningtoachieveflatness



•   T‐beamscanbefabricatedfromplateusinganyapprovedweldingprocess.

•   Widevarietyofflangeandwebthicknesscombinationstosuitdesigngoals

•   Reducedinventory–canusefewercommonplatethicknesses.

•   Fabricatedshapescanresultinasignificantweightreduction(10‐30%atequalstrength).

•   Greateravailablevarietyofsteelgrades=greaterweightsavingspossible.

9.0# AH-36 I/T Replaced by 6.3# DH-36 Fabricated Tee (33% wt. savings)


ApplicationCaseHistory#2WhyHLAW?

•   T‐beamscanbefabricatedfromplateusinganyapprovedweldingprocess.

•   Conventionalprocesses:–   Availabletodayandeasilyqualified

•   Conventionalprocesses:–   TheGood:

•   Lowercostequipment,greaterfamiliarity

–   TheBad:•   Lowerweldingspeeds,higherheatinputs

–   TheUgly: •   Morepronetodistortion,lesspredictable•   Lighterbeams&high‐yieldsteelsdistortevenmore.



SmallPortionofTestArticlePopulation

VerificationofProcessandProductPerformance



Attribute Thickness Results

Visual Inspection 0.188, 0.250, 0.313, 0.375 Satisfactory

Magnetic Particle Inspection 0.188, 0.250, 0.313, 0.375 Satisfactory

Radiographic Inspection 0.188, 0.250, 0.313, 0.375 Satisfactory

Transverse Tensile 0.188, 0.250, 0.313, 0.375 Satisfactory

Root Face & Side Bends 0.188, 0.250, 0.313, 0.375 Satisfactory

Nominal Heat Input 0.188, 0.250, 0.313, 0.375. 10-12 kJ/in. (3 Heat inputs represent High, Mid, Low bounds)

Macro-section Evaluation 0.188, 0.250, 0.313, 0.375 Satisfactory

Micro-hardness 0.188, 0.250, 0.313, 0.375 Informational (Avg. < 350 VHN)

Tee-Tension Test 0.188, 0.250, 0.313, 0.375 Informational (Sim. to ASTM A-769) - Sat

Charpy V-Notch Evaluation @ -20F 0.313, 0.375 Sub-size specimens

Informational: Weld (Avg. ~ 145 ft-lb. @ -20F) HAZ (Avg. ~50 ft-lb. @ -40F)

E70S‐6electrodeCVNrequirement=35ft‐lb.@‐20F;Mfr.testsshow~60‐70ft‐lb;HLAWaverages~145ft‐lb.


DiffusibleHydrogenCharacteristicsofHLAW

DiffusibleHydrogenConsiderations

  Diffusiblehydrogenmaycausecrackinginwelds

  HLAWmayproduceweldandHAZareasthataresensitivetohydrogendamage

  HLAWwillbeappliedtohigher‐yieldsteelsthatarehydrogen‐sensitive

  LimitedpublishedworkforLBW

  NopriordataonHLAW



Hydrogen“Potential”

  LBWconsidered“lowhydrogenprocess”

  Grigoryants(1996):   LimitedtimeforHdiffusionintotheweld

  Whitney:ICALEO2000–LBWtesting

  Verylowhydrogenforwelds“inair”

  HLAWnotpreviouslytested

  Additionalheatsourcemakeslargerweld

  HigherspeedsmaylimitHdiffusionintoweld


DiffusibleHydrogenCharacteristicsofHLAW TestPlan

•   TestinginaccordancewithAWSA4.3•   Productionwiretakenfromwarehousestock

–   ESAB“Coreweld110”•   BaselineH2testsperformedatESAB,Hanover,PA

–   WirespoolshippedtoATSfortesting

•   “Gaschromatograph”measurementofevolvedhydrogen•   CouponspreparedatESAB,shippedtoATS•   ShieldinggasdewpointcheckedatATS&ESAB•   ESABtestsduplicatedatATS•   VariousHLAWparametersetsperformedoncoupons

•   VariousautogenousLBWprocedures

•   CouponsshippedtoESABunderliquidnitrogenforHevolution



StandardAWSA4.3DiffusibleHydrogenTestCouponConventionalGMAWeldBead

As‐weldedCouponMacroofWeldBead



TestWeldCouponinCopperVise‐Jaws



ShieldingGasDewPointTesting

ExperimentalSet‐up


DiffusibleHydrogenTestResultsESAB“CoreWeld110”

ProcessFillerMetal

ProgressionLaserPower

WFS Amps VoltsWeldSpeed

AvgH2ml

H2ml/100gm

Comments

n/a n/a n/a n/a n/a n/a n/a n/a 0 n/aUnweldedspecimenstodetermineifHydrogenpickuphasoccurreddueto

exposure

GMAW CW‐110GMAW‐withDragangle

n/a 430 280 30 14 0.493 2.7DuplicateoforiginalESABtestperformedatHanover(2.5)

LBW None Autogenous 7 n/a n/a n/a 14 0.015 n/aAutogenousWeldHydrogenpickupat

travelspeedofESABGMAW

LBW None Autogenous 7 n/a n/a n/a 50 0 n/aAutogenousWeldHydrogenpickupat

mid‐rangetravelspeed

LBW None Autogenous 7 n/a n/a n/a 80 0 n/aAutogenousWeldHydrogenpickupat

typicalHLAWtravelspeed

HLAW CW‐110 Laser‐Leading 7 600 328 30 80 0.038 0.9HLAWHydrogenpickupatrecentPQR

parameters(ATSID#3525)

HLAW CW‐110 Laser‐Leading 3.5 600 314 27.5 75 0.053 1.1HLAWHydrogenpickupatrecent

lightweightTeeweldingparameters(ATSID#3597)

HLAW CW‐110 Laser‐Leading 7 430 270 30 80 0.023 0.8HLAWHydrogenpickupatPQR

parametersbutwithESABGMAWwirefeedspeed

HLAW CW‐110 GMA‐Leading 7 600 310 30 80 0.07 1.8HLAWHydrogenpickupatPQR

parametersbutwithGMAWleading


DiffusibleHydrogenTestResultsMil‐100S‐1(ESAB“Spool‐Arc95”)

test# Process

FillerMetal

Progression

LaserPowerWFS I

Volts(+/‐1)

WeldSpeed

AvgH2ml

Avg.H2ml/

100gmComments

1 GMAW 100S‐1 push n/a 300 26 12 0.191 1.21 Duplicateoforiginal‐push

2 GMAW 100S‐1 drag n/a 300 26 12 0.236 1.52 Duplicateoforiginal‐drag

3 GMAW 100S‐1 drag n/a 300 26 40 0.077 1.59 ESABParametersathighertravelspeed

4 GMAW 100S‐1 drag n/a 300 26 80 0.044 1.89 ESABParametersathighertravelspeed

5 HLAW 100S‐1 Laserlead 7 300 26 80 0.035 2.11 HLAWatESABParametershighertravel

6 HLAW 100S‐1GMAWlead 7 600 28 80 0.086 2.00 HLAW,higherWFS,highertravelspeed

7 HLAW 100S‐1 Laserlead 5 600 28 120 0.048 1.76 HLAW,LowerHeatInput,hightravelspeed

8 HLAW 100S‐1GMAWlead 5 600 28 120 0.059 2.13 HLAW,LowerHeatInput,hightravelspeed

9 HLAW 100S‐1 Laserlead 7 600 28 70 0.050 0.98 HLAW,higherHeatInput,lowertravelspeed

10 HLAW 100S‐1GMAWlead 7 600 28 70 0.071 1.41 HLAW,higherHeatInput,lowertravelspeed

11 LBW n/a n/a 7 n/a n/a 15 0.072 AutogenousattravelspeedofWhitney

12 LBW n/a n/a 7 n/a n/a 80 0.000 Autogenousathigherpowerandhighertravel

13 LBW n/a n/a 3 n/a n/a 40 0.005AutogenousatWhitneyparametersexcept

highertravel

14 LBW n/a n/a 3 n/a n/a 15 0.007 AutogenousatWhitneyparameters


ResidualHydrogenTestResults

Are the low hydrogen results due to trapped hydrogen in pores? Remove excess material RT to determine pore locations Cut segments to capture large, small, & no pores Perform vacuum hot-gas extraction Determine hydrogen concentration

Specimen shown, Autogenous LBW @ 7 kW, 15 ipm Diffusible hydrogen value = 0.07 ml/100 gram of total melt Residual hydrogen values shown per location below

2.7 ppm

1.5 ppm

0.2 ppm


DiffusibleHydrogenTestingConclusions

•   ATSprocessverifiedtomatchESAB&AWSA4.3

•   AutogenousLBWexhibited“lowtono”pickup–  Lowerspeed(14ipm)showedlowpickup–  Higherspeeds(50&80ipm)showednopickup

•   HLAWproceduresshowlowHpickup–  LessProportionaltowirefeedspeed–  Laser‐leadH2lower(0.9‐1.1)thanGMAW(2.5)

–  GMAW‐leadH2closer(1.8)toGMAW(2.5)

•   TotalQuantityofH2lowerforHLAW


WeldFumeEvolutionCharacteristicsofHLAW

AirborneFumeEmissionProfilesofHybridLaserArcWelding(HLAW)

DanielO.Chute,CIH,CSP,AtriumEnvironmentalHealthandSafetyServices,LLC,

andPaulBlomquist,

AppliedThermalSciences,Inc.



•   Establishedexposurelimitsprescribedformanymetalswhichmaybefoundinsteelweldingoperations,includingOSHAcomprehensivehealthstandardsfor–   Pb,–   HexCr,–   Cd–   andMn.

•   Somerecentliteraturehaswarnedofpotentialforexposureinexcessoflimitsduringroutineweldingoperations

•   NIOSHhasbeenengagedsince2002inongoingstudiesontheHealthEffectsofWelding.



Whydothis?•   Verifythatemployeesarenotatrisk

•   Complywithhealth&safetyregulationsBut:•   Thereisfumedataforconventionalweldingprocessesavailableinthetechnicalliterature,

•   Nodefinitivepreviouslypublisheddataonfumelevelsgeneratedinthewelder’sbreathingzoneduringHybridLaserArcWelding(HLAW).



•  GMAweldedjointS690QL



•  Weldingspeed0,1..0,3m/min/layer

•  Angulardistortion:high•  DimensionWMandHAZ:wide

•  Laser‐GMA‐hybridweldedjointS690QL



•  Weldingspeed1,5m/min

•  Angulardistortion:low•  DimensionWMandHAZ:narrow

Photos&Data:GSI‐SLV



OtherHLAWAdvantagesGMAW:

•  Weldspeed:12‐18ipm

•  Longertimeperpass

•  WelderPBZnearthearc

•  Fumepath:

•  Random,oftentowardwelder

•  Auxiliaryfumeextraction:

•  Mustbeconstantlymovedbywelder

HLAW

•  WeldingSpeed50‐150ipm

•  Lesstimeperpass

•  OperatorPBZremotefromarc

•  Fumepath:

•  AirKnifeBlowsfumeaway

•  Auxiliaryfumeextraction:

•  Constantrelationshiptoweldpool



•   Workwasconductedinaweldingproductionshopwhichincludedothermetalworkingandfinishingoperationssuchas:–   grinding;–   enclosedabrasiveblasting;and,–   TIGweldingandmachining.

•   TheHLAWworkwasdoneinagantryroom.



•   AllairsampleswerecollectedbyaCIH–   inaccordancewithOSHAMethod

125G/NIOSH7300–   using35mmMCEfilter,0.8micron

poresize.•   AnalysiscompletedbylabAIHA

Accreditedformetals.

•   TestingincludedbothPBZandAreaairsamplescollectedunderthefollowingoperatingconditions:–   Metaltype/thickness;–   Fillermetal/wire;–   Arccurrent&timeperweldcycle;–   LaserStrength/wavelength;and,–   Gasflow.



MetalsMeasured

•   Cadmium(fume) •   Cobalt •   Chromium •   Copper(fume) •   Lead •   Manganese •   Nickel •   IronOxidefume •   ZincOxidefume



ProcessesObserved •   Plasmacuttingofcarbonsteel •   Abrasiveblastingoncarbonsteel•   Anglegrindingoncarbonsteel •   Tungsteninertgas(TIG)welding •   HybridLaserArcWeldingoncarbonsteel •   HybridLaserArcWeldingonstainlesssteel •   Areasforobserversandbystanders


WeldFumeEvolutionTestResults

•   Over59hoursofsamplingforCadmium(fume);Cobalt;Chromium;Copper(fume);Lead;Manganese;Nickel;IronOxide(fume);ZincOxidefume

•   AllairsampleresultswerebelowOELfortheninemetalstestedineachairsample.

•   AllresultsbelowPELBrokendownbyanalyteMaximumFractionofPEL


HLAWFumeCharacteristics 2008HLAWStudy


HLAWFumeCharacteristics MnConcentration‐NSRP1999vs.HLAW08‐09

892.6

114.7 152.5

24.6 14.75 28.5 9.83 31 15.7

0

100

200

300

400

500

600

700

800

900

1000 FC

AW (1

)

GM

AW (1

)

SM

AW (1

)

HLA

W o

n C

arbo

n S

teel

(2

)

HLA

W o

n H

SLA

65

Ste

el

with

70S

Wire

(2

)

HLA

W o

n H

SLA

80

Ste

el

with

Cor

ewel

d W

ire (2

)

HLA

W o

n S

tain

less

Ste

el

Fum

e E

xtra

ctor

O

ff (2

)

HLA

W o

n S

tain

less

Ste

el

Fum

e E

xtra

ctor

O

n (2

)

HLA

W o

n H

SLA

80

No

Lev

(3)

Mn

Con

cent

ratio

n, µ

g/m

3


HLAWFumeCharacteristics MnConcentration–ByParticleSize


HLAWFumeCharacteristicsConclusions

BaselineairmonitoringdataduringHLAWEvaluatedexposuretoninemetalsVarietyofoperatingconditions.HLAWproducedverylowoperatorexposureExposuresmayvaryaccordingtouseof

localexhaustventilation,arctime,metalthicknessandfillermetal


•   Recommendedadditionalwork–  Performfumeparticlesizeanalysis

–  Extendtestingtocoveradditionalalloys

HLAWFumeCharacteristicsConclusions


Questions?

(hlaw) - american welding society · laser + cold wire feed: ... hybrid & tandem laser arc...

Documents