the major constraint standard over the road: –4.1 m high by 2.6 m wide –net weight 21 tons very...

The Major Constraint

• Standard over the road:– 4.1 m high by 2.6 m wide – Net weight 21 tons

• Very expensive– > 4.83 m high

• Rail– 3.4 m, and heights are limited to 4.0 m.

Available Materials

Welding 2

Global Wind Tower Solutions Typical Wind Tower Plant

Plate Storage&

QualityPlate Rolling and

Tacking (1 X MIG)

Longitudinal Welding

(1 X SAW)

Circumferential Welding

Flange to CanRing to CanCan to Can(2 X SAW)

Doorway Welding

(2 X SAW)

Fittings & QA(2 X MIG)

100% UT

Sand Blast

Paint Or

(2 X FCAW)

InternalsAluminum

Counter weight

(1 X MIG)

Cutting

Boxes With a Red Border Indicate Processes Involving WeldingCourtesy: Lincoln Electric

FACILITY AUTOMATION CONSIDERATIONSFACILITY AUTOMATION CONSIDERATIONS

Wind Tower Welding Productivity SeminarWind Tower Welding Productivity Seminar

• Establish Requirements, Develop Concepts, and Model Concepts.• Ensure that the Process Flow and Facility expectations can be achieved with the equipment

specified..

• Establish Requirements, Develop Concepts, and Model Concepts.• Ensure that the Process Flow and Facility expectations can be achieved with the equipment

specified..

Tower Manufacturing

www.davi.com

http://www.directindustry.com/prod/davi-promau/sheet-metal-calendering-line-for-wind-tower-16273-367798.html

Welding 7

Weldment• Weldment has three distinct zones

– fusion zone• area of weldment that melted and resolidified

• contains base and filler metal

– HAZ• area of weldment that did not melt, but properties has

changed due to the heat input

• contains base metal

– base metal • area of weldment that was unaffected by weld• contains base metal (obviously)

Welding 8

From Lincoln Electric

Welding 9

HAZ

• Dependent on:– type of alloy– heat added– initial heat– cooling rate

Kalpakijan & Schmid: Manufacturing Engineering and Technology”

Welding 10

GMAW (MIG)• Continuous solid wire electrode

• shielding from outside source of gas– Ar, He, CO2, or most likely a mixture

• weld metal also contains deoxidizers– improves weld quality

• lends itself well to robotics

Welding 11

Groover: “Fundamentals of Modern Manufacturing”

Welding 12

FCAW (Flux Core)• Continuous tubular electrode

• Shielding from:– solid flux in the middle– external shielding gas

• Advantages over GMAW:– 4 to 8 X deposition rate out of position– 1.5 X deposition rate in position

• especially for weldments greater than .5”

– alloy opportunities by changing fluxFigure from Lincoln Electric

Welding 13

SSFCAW (Self Shielded Flux Core)• Continuous tubular electrode

• Shielding from solid flux in the middle

• Advantages over GMAW:– outdoor applications– alloy opportunities by changing flux

Welding 14

SAW (Submerged Arc)• Continuous solid wire electrode

• granular flux:– shielding– prevents spatter and sparks– insulation to allow deeper penetration

• flat or horizontal position, circular

• good quality, toughness, uniform properties

• usually automated

Welding 15

Figure from Groover

Welding 16

Cary: Modern Welding Technology

Welding 17

Residual Stress• caused by contraction of metal during

solidification and cooling

• control or minimize by:– fixtures– procedures (order of welds)– parameters (speed, filler metal . . – preheat– stress relief– proper design

Figure from Lincoln Electric

Global Wind Tower Solutions

• Can be welded with a variety of processes, but most commonly SAW or FCAW.

• FCAW equipment recommendation:– CV400/LN-7 Pro

• FCAW consumable recommendation:– UltraCore® E71T-12

• Handheld SAW is preferred, but flux selection is critical due to metallurgical requirements, and flux feedability concerns.

• Handheld equipment recommendation:– LN-9 Undercarriage with Flux Feeding System,

combined with Idealarc® DC-600 or DC-655• Handheld consumable recommendation

– Lincolnweld® L-61 with 860, 960, or WTX™ Flux

Entry Door Frame Welding

Slide from Lincoln Electric

• Change Joint Configuration• Decrease Joint Angle• Increase Joint Land• Improve Weld Procedure• Use AC to Increase Deposition• Eliminate Back Gouging• Improved Energy Efficiency with

Power Wave® Technology

Cost Reduction SavingsPotential In Summary

36mm

6mm

50º

AFTER

36mm Plate




• Typically Tandem, triple Tandem or Twin Tandem systems, utilizing 2, 3 or 4 wires and welding heads.

• With 2 or 3 wire Tandem Arc these welds can be accomplished single pass per side up to 36 mm.

• Multi-pass welds are used when there is poor fit-up, greater plate thickness and to improve weld toughness.

• With 3 wires, single pass thickness of up to 40 mm may be achieved.

• The Included Angle used on Bevels for Tandem Arc can be greatly decreased to 50o maximizing productivity and enabling single pass per side welding.

• Lincoln Electric Power Wave® AC/DC 1000® power sources are ideal in these applications, with proven productivity and quality increases, as well as the opportunity for significant cost reduction.

Longitudinal & Circumferential Welding Review



• Transferring technologies developed for the pipeline industry, in 2002 Lincoln Electric developed a new procedure for Apoyos Metalicos

• The new procedure replaced a 9-pass single arc approach with a 2-pass tandem arc procedure

• Switched from CV to CC• Consumable recommendation for impacts at -

20oC; Lincolnweld® P230, P223, or WTX™ flux with Lincolnweld® L-61 wire

• Consumable recommendation for impacts at -40oC; Lincolnweld® WTX™ flux with Lincolnweld® L-61 wire

• Cost Savings – greater than 50% reduction in weld time and consumable savings

Customer Success

70º

36mm2mm

BEFORE

36mm6mm

50º

AFTER

13mm Plate 19mm Plate 36mm Plate


It is important to note that an effective automation “strategy” seamlessly ties together all of the necessary components

- Controls- Fixturing- Power Supplies- Sensing- Process Monitoring- Networking- User Interface

to consistently provide the desired cost and quality benefits. Each component needs to be considered to ensure it is not the weak link of the overall completely integrated system.

INTEGRATED SYSTEMS STRATEGYINTEGRATED SYSTEMS STRATEGY

Wind Tower Welding Productivity SeminarWind Tower Welding Productivity SeminarSlide from Lincoln Electric

• Supplier experience in Welding Automation Controls, as well as systems integration specifically for your application, will significantly help to ensure requirements are met and mistakes are not repeated.

What is Important to Consider when Evaluating Automation- Experience -

What is Important to Consider when Evaluating Automation- Experience -

Unless your application is very unique, try not to be the guinea pig

Wind Tower Welding Productivity SeminarWind Tower Welding Productivity Seminar

Process-Power Supplies-Sensors-Motion-etc.


26

Improving Subarc welding productivity

• Productivity depends on:

– Deposition rate– Set up time / operator skill– Fit up and edge prep– Steel quality / property requirements– Other bottlenecks– Defect Costs

• Severity• Occurrence• Detection

27

SAW Deposition RatesSingle Electrode DC+

Diameter Current Deposition

Rate

2.4mm 600 Amps 8 Kg/hr




10 to 12 kg/hr is the baseline

28

SAW Deposition Rates Twin Arc

Diameter Current Deposition Rate

2 x 1.6mm 980 Amps 17Kg

2 x 2.0mm 1300 Amps 18Kg

2 x 2.4mm 1400 Amps 19Kg

50% increase in deposition rate versus single wire DC+

• Power source must be capable and stable at high currents• Loss in penetration (return to back gouging…)• Good when fit up / joint preparation is not perfect• Can be used in tandem with single wire or another twin

29

SAW Deposition RatesMultiple Arcs

Number Deposition of Arcs Configuration rate 1 DC+ 12 Kg/hr

2 DC+/AC 22 Kg/hr

3 DC+/AC/AC 32 Kg/hr

4 DC+/AC/AC/AC 52 Kg/hr

5 DC+/AC/AC/AC/AC 63 Kg/hr

Huge increases in deposition rate versus single wire DC+

High penetration allows modified joint design

One pass per side decreases set up time

30

Flux/wire consumptionFlux/wire consumption

Weld volume

V-butt joint V-butt joint X-butt joint X-butt joint

Thickness Volume

12 mm 0.41 Kg/m 14 mm 0.60 Kg/m 16 mm 0.79 Kg/m 18 mm 1.03Kg/m 20 mm 1.45 Kg/m 22 mm 1.76 Kg/m

bevel angle:60º

root face: 6 mm

Bevel angle: 60º

root face: 6 mm

Thickness Volume

12 mm 0.19 Kg/m 14 mm 0.29 Kg/m 16 mm 0.41 Kg/m 18 mm 0.61 Kg/m 20 mm 0.70 Kg/m 22 mm 0.87 Kg/m

32

Example of a 4-wire SAW Procedure

• Lead arc: DC+ 1000 amps, 32 volts• Second arc: AC 900 amps, 35 volts• Third arc: AC 800 amps, 38 volts• Fourth arc: AC 725 amps, 41 volts

• All wires are 4.0 mm diameter• All heat inputs are essentially the same

33

4 Wire SAW Example: Lead Arc

• In most cases the lead arc is DC+

• The low voltage focuses the arc current (resulting in deep penetration). Can provide up to 80% of the total penetration.

34

4 Wire SAW Example: Arc 2

• The second arc increases penetration because of the proximity to the first arc.

• Lower current, higher voltage produces a wider, shallower bead profile.

35


• Current lower than Arc 2; voltage higher.

• This layer adds to the width of the bead. It should bring the weld metal approximately to the surface.

36


• Usually characterized by the lowest current and highest voltage.

• Shapes the cap of the weld. Angle of electrode, voltage, current and flux type determine toe angles, cap height, shape.

37

Finished Weld

• The sketch shows the complete weld bead (with a tack weld).

• The heat input of each arc was very similar, but different shapes were created by manipulation of volts, amps, spacings and angles.

The Major Constraint

• Standard over the road:– 4.1 m high by 2.6 m wide – Net weight 21 tons

• Very expensive– > 4.83 m high

• Rail– 3.4 m, and heights are limited to 4.0 m.

Modular Bolted

Cast Weld Falk Lüddecke, Werner Rücker, Marc Seidel, Jens Assheuer: Tragverhalten von Stahlgussbauteilen in Offshore-Windenergie-Anlagen unter vorwiegend ruhenderund nicht ruhender Beanspruchung

the major constraint standard over the road: –4.1 m high by 2.6 m wide –net weight 21 tons very...

Documents