Using the Time Twin Process to Improve Quality

Using the Time Twin Process to Improve Quality and Reduce Costs in High Deposition Welding of Thick Section Aluminium Mike Ludwig Market Segment Manager Shipbuilding & Power Generation Fronius USA - Welding Division 1 Fronius USA / Mike Ludwig / AWS Shipbuilding Conference 2011 / xx. 201 x

Outline / Introduction / Technical Requirements / Approach / Results / Conclusions 2 Fronius USA / Mike Ludwig / AWS Shipbuilding Conference 2011 / xx. 201 x

Acknowledgements / Work done by Fronius International R&D Group / Contributors: / Christoph Kammerhuber, International Shipbuilding Segment Manager / Stephen Egerland, International Pipeline/Offshore Segment Manager 3 Fronius USA / Mike Ludwig / AWS Shipbuilding Conference 2011 / xx. 201 x

Liquefied Natural Gas (LNG) / Increasing importance of Natural Gas in Energy Sector / Storage a/o transport over long distances / Significant volume reduction by liquefaction / Approximately 1/600 of the original volume at temperatures of approx. – 162°C / Different methods to transport LNG 4 Fronius USA / Mike Ludwig / AWS Shipbuilding Conference 2011 / xx. 201 x

Liquefied Natural Gas Containment Vessels (LNG) / Excellent method for LNG long distance transport / Globally applicable Source: Hyundai Heavy Industries / Economically reasonable due to increasing storage capacities / Great engineering expertise and capital equipment for vessel construction 5 Fronius USA / Mike Ludwig / AWS Shipbuilding Conference 2011 / xx. 201 x

LNG Vessel Construction Principles © TOSAKA Sphere (Moss Type) 6 Membrane Fronius USA / Mike Ludwig / AWS Shipbuilding Conference 2011 / xx. 201 x

LNG Carrier – Membrane Containment Type / Base Material: 64 Fe. Ni (Invar 36©) / Filler Material: Ni. Mo 28 Fe 4 Cr (~ S Ni 1069 acc. to DIN EN ISO 18274) / Peculiarities: / Welding Process: Plasma Arc Welding (PAW) and Gas Tungsten Arc Welding (GTAW) / ‘Difficult‘ to weld (Highly skilled welders needed) / Heat Input to be monitored accurately 8 / Leak detection difficult to perform Fronius USA / Mike Ludwig / AWS Shipbuilding Conference 2011 / xx. 201 x

SPB > Self-supporting Prismatic-shape IMO B 9 Fronius USA / Mike Ludwig / AWS Shipbuilding Conference 2011 / xx. 201 x

SPB > Self-supporting Prismatic-shape IMO B / Intermediate principle between Membrane and Spherical Type / Aluminum Alloy Construction / Wall Thickness: ≦ 25 mm / Benefits: / Good Hull Stability / Low Centre of Gravity / Low Boil-Off Rate / Good Maintenance Conditions 10 Fronius USA / Mike Ludwig / AWS Shipbuilding Conference 2011 / xx. 201 x

LNG Carrier – Spherical Containment Type / Spheres as LNG Containments / Construction is based on the Kvaerner-Moss Type Principle © TOSAKA / Aluminum alloys are used as base materials / Four-Tank Design for Cargo Operation Improvement Source: KAWASAKI Heavy Industries 11 / Storage Capacity slightly below Membrane Containments Fronius USA / Mike Ludwig / AWS Shipbuilding Conference 2011 / xx. 201 x

LNG Sphere Containment Construction / Benefits: / Manufacturing may occur separately to hull-construction / Increased use of semi-automated welding processes / Higher production rates Source: KAWASAKI Heavy Industries 12 / Improved test and repair conditions Fronius USA / Mike Ludwig / AWS Shipbuilding Conference 2011 / xx. 201 x

Outline / Introduction / Technical Requirements / Approach / Results / Conclusion 13 Fronius USA / Mike Ludwig / AWS Shipbuilding Conference 2011 / xx. 201 x

It was required to. . . / / / Source: KAWASAKI Heavy Industries 14 Improve welding process conditions: Improve weld quality Increase process efficiency Reduce production costs Investigate High Performance Time Twin MIG Welding to replace manual MIG Welding and make Time Twin suitable for out-of-position welding applications in LNG Sphere Containment Manufacturing Fronius USA / Mike Ludwig / AWS Shipbuilding Conference 2011 / xx. 201 x

Project Goals: / To investigate and evaluate the welding of thick section Aluminium using the MIG single wire & Twin Time (Tandem) welding process in common welding positions and under common welding process conditions / To develop and design a special Single & Tandem Torch for the welding in reduced weld preparation on thick section Aluminium 15 Fronius USA / Mike Ludwig / AWS Shipbuilding Conference 2011 / xx. 201 x

Outline / Introduction / Technical Requirements / Approach / Results / Conclusion 16 Fronius USA / Mike Ludwig / AWS Shipbuilding Conference 2011 / xx. 201 x

From where we got started. . . / Traditional manual MIG Welding / Push-Pull Torches required / Usual wire diameters (1. 6 mm) / CV Spray Arc / Highly Skilled Welders / Quality limitations 17 Fronius USA / Mike Ludwig / AWS Shipbuilding Conference 2011 / xx. 201 x

Equipment for single wire MIG welding trials Robacta Drive Torch RCU 5000 i 18 TPS 7200/9000 Welding System Fronius USA / Mike Ludwig / AWS Shipbuilding Conference 2011 / xx. 201 x

Semi-Automatic single wire MIG welding / Filler Wire: AA 5183 (Al. Mg 4, 5 Mn) 2, 0 mm / Base Material: AA 5356 (Al. Mg 5) / Dimension: 500 x 250 x 30 mm / (no preheating permitted) / Shielding Gas: Ar 70/He 30 / Welding Speed: 40/45 cm/min / Welding Position: 1 F / Two layers / second layer > two weld beads 19 Fronius USA / Mike Ludwig / AWS Shipbuilding Conference 2011 / xx. 201 x

Semi-Automatic single wire MIG welding / Filler Wire: AA 5183 (Al. Mg 4, 5 Mn) 2, 0 mm / Base Material: AA 5356 (Al. Mg 5) / Dimension: 500 x 250 x 30 mm / (no preheating permitted) / Shielding Gas: Ar 70/He 30 / Welding Speed: 40/40 cm/min / Welding Position: 1 F / Two layers / second layer > oscillated 20 Fronius USA / Mike Ludwig / AWS Shipbuilding Conference 2011 / xx. 201 x

Semi-Automatic single wire MIG welding / Filler Wire: AA 5183 (Al. Mg 4, 5 Mn) 2, 0 mm / Base Material: AA 5356 (Al. Mg 5) / Dimension: 500 x 250 x 30 mm / (no preheating permitted) / Shielding Gas: Ar 70/He 30 / Welding Speed: 22, 5 cm/min / Welding Position: 2 F / One layer 21 Fronius USA / Mike Ludwig / AWS Shipbuilding Conference 2011 / xx. 201 x

Semi-Automated Single Wire MIG-Welding / New developed torch parts (gas nozzle, contact tip, wear parts) / Filler Wire: AA 5183 (Al. Mg 4, 5 Mn) 2. 0 mm / Base Material: AA 5356 (EN AW Al. Mg 5) / Dimensions: 500 x 250 x 35 mm / (no preheating permitted) / / 22 Shielding Gas: Ar 70/He 30 Welding Position: 2 G Welding Speed: 60 cm/min Especially developed Welding Characteristic Fronius USA / Mike Ludwig / AWS Shipbuilding Conference 2011 / xx. 201 x

Fully-Automatic single wire MIG welding / Filler Wire: AA 5183 (Al. Mg 4, 5 Mn) 1, 6 mm / Base Material: AA 5356 (Al. Mg 5) / Dimension: 500 x 250 x 15 mm / (no preheating permitted) / Shielding Gas: 100% Ar. / Welding Speed: 25 cm/min / Welding Position: 2 F / One layer > oscillated 23 Fronius USA / Mike Ludwig / AWS Shipbuilding Conference 2011 / xx. 201 x

Fully-Automatic single wire MIG welding / Filler Wire: AA 5183 (Al. Mg 4, 5 Mn) 1, 6 mm / Base Material: AA 5356 (Al. Mg 5) / Dimension: 500 x 250 x 15 mm / (no preheating permitted) / Shielding Gas: 100% Ar. / Welding Speed: 22, 5 cm/min / Welding Position: 3 F Vertical up / One layer > oscillated 24 Fronius USA / Mike Ludwig / AWS Shipbuilding Conference 2011 / xx. 201 x

Fully-Automatic single wire MIG welding / Filler Wire: AA 5183 (Al. Mg 4, 5 Mn) 2, 4 mm / Base Material: AA 5083 (Al. Mg 4, 5 Mn) / Dimension: 500 x 150 x 25 mm / (no preheating permitted) / Shielding Gas: Ar 70/He 30 / Welding Speed: 60/40 cm/min / Welding Position: 1 F / four layers > 8 weld beads 25 Fronius USA / Mike Ludwig / AWS Shipbuilding Conference 2011 / xx. 201 x

Fully-Automatic single wire MIG welding / Filler Wire: AA 5183 (Al. Mg 4, 5 Mn) 2, 4 mm / Base Material: AA 5083 (Al. Mg 4, 5 Mn) / Dimension: 500 x 150 x 25 mm / (no preheating permitted) / Shielding Gas: Ar 70/He 30 / Welding Speed: 38 cm/min / Welding Position: 1 G / Two layers > oscillated / one layer from each side 26 Fronius USA / Mike Ludwig / AWS Shipbuilding Conference 2011 / xx. 201 x

Fully-Automatic single wire MIG welding / Filler Wire: AA 5183 (Al. Mg 4, 5 Mn) 2, 4 mm / Base Material: AA 5356 (Al. Mg 5) / Dimension: 500 x 15 mm / (no preheating permitted) / Shielding Gas: Ar 70/He 30 / Welding Speed: 60/40 cm/min / Welding Position: 1 G / Two layers / second layer > oscillated 27 Fronius USA / Mike Ludwig / AWS Shipbuilding Conference 2011 / xx. 201 x

Metallographic Results of Single Wire MIG Welding Trials Position 2 G 28 Position 3 G Fronius USA / Mike Ludwig / AWS Shipbuilding Conference 2011 / xx. 201 x

Single Wire MIG Welding Procedure: 3 GPosition 29 Fronius USA / Mike Ludwig / AWS Shipbuilding Conference 2011 / xx. 201 x

2006 – The very first humble steps in Single-Wire MIG Welding / Manual welding torch on ‘quasi-similar‘ joint geometry / Wire diameter: AA 5183 ( 1. 6 mm) / Base material: AA 6061 (Al. Mg. Si) / Thickness: 15 mm 30 Fronius USA / Mike Ludwig / AWS Shipbuilding Conference 2011 / xx. 201 x

. . . and the results 31 Fronius USA / Mike Ludwig / AWS Shipbuilding Conference 2011 / xx. 201 x

Next Step – Fundamental Investigations on Manual MIG 32 Fronius USA / Mike Ludwig / AWS Shipbuilding Conference 2011 / xx. 201 x

The Tool and the Outcome 33 Fronius USA / Mike Ludwig / AWS Shipbuilding Conference 2011 / xx. 201 x

Outline / Introduction / Technical Requirements / Approach / Twin Welding / Conclusion 34 Fronius USA / Mike Ludwig / AWS Shipbuilding Conference 2011 / xx. 201 x

Time Twin – Tandem High Performance MIG Welding / Fully Synchronised welding system. / 2 digital power sources / 2 wire feeders / 2 separate electrode potentials / 1 high duty cycle welding torch / All linked by a high speed bus *LHSB = Local High Speed Bus 35 Fronius USA / Mike Ludwig / AWS Shipbuilding Conference 2011 / xx. 201 x

Equipment Time Twin Torch Tripod Unit Time Twin Welding System RCU 5000 i 36 Oscillation Unit Fronius USA / Mike Ludwig / AWS Shipbuilding Conference 2011 / xx. 201 x

Time Twin High Performance Tandem Welding System / Commercially available Tandem Welding System / Especially shaped gas nozzle / Varying arc-gaps during the weld trial series / Column and Boom System for mechanized torch motion / Implementation of weaving motion / Trials started under using regular welding characteristic 37 Fronius USA / Mike Ludwig / AWS Shipbuilding Conference 2011 / xx. 201 x

Specific LNG Containment Narrow Gap Weld Sequence / Specifically developed for LNG sphere containment heavy wall applications / Considerable reduction of weld metal deposition rate / Considerable reduction of operation time / Limited suitability for semiautomated welding processes 38 Fronius USA / Mike Ludwig / AWS Shipbuilding Conference 2011 / xx. 201 x

Modified Narrow Gap Design Diagram with permission of Norrish, J. – ‘Advanced Welding Processes‘, © IOP Publishing 1992 39 Fronius USA / Mike Ludwig / AWS Shipbuilding Conference 2011 / xx. 201 x

Tandem Welding – Electromagnetic Interferences Source: UEYAMA, T. , ‘Occurrence of Arc Interference and Interruption in Tandem Pulsed GMA Welding‘ IIW Doc. No. XII-1883 -06 40 Fronius USA / Mike Ludwig / AWS Shipbuilding Conference 2011 / xx. 201 x

Electromagnetic Interference – A Closer View. . . 41 Fronius USA / Mike Ludwig / AWS Shipbuilding Conference 2011 / xx. 201 x

Improved Tandem MIG Welding Characteristic 42 Fronius USA / Mike Ludwig / AWS Shipbuilding Conference 2011 / xx. 201 x

Advanced State of Research and Development / Specifically modified narrow gap gas nozzle, contact tips and wear parts / Excellent narrow gap root access / Adjusted tip or arc gap assures high process stability / Stable and sound weld pool controllability / Appropriate nozzle cooling yields good resistance against thermal impact 43 Fronius USA / Mike Ludwig / AWS Shipbuilding Conference 2011 / xx. 201 x

New Developed Narrow Gap Tandem Torch 44 Fronius USA / Mike Ludwig / AWS Shipbuilding Conference 2011 / xx. 201 x

Time Twin Welding in 3 G Position 45 Fronius USA / Mike Ludwig / AWS Shipbuilding Conference 2011 / xx. 201 x

Reducing the number of layers. . . / Total number of weld layers was required to be reduced from 8 (workshop-condition) down to 6 / 7 front side + 2 rear side layers were achieved at the trials beginning using Time Twin High Performance welding in 3 Gposition / Continuous reduction of layer number could be obtained by improving welding conditions and -sequence 7 front side layer trial 46 Fronius USA / Mike Ludwig / AWS Shipbuilding Conference 2011 / xx. 201 x

Final Weld Joint Configuration … 47 Fronius USA / Mike Ludwig / AWS Shipbuilding Conference 2011 / xx. 201 x

Final Weld Sequence … 60 48 Fronius USA / Mike Ludwig / AWS Shipbuilding Conference 2011 / xx. 201 x

Variables / Filler Wire: AA 5356 (Al. Mg 5) 1, 6 mm / Base Material: AA 5356 (Al. Mg 5) / Dimension: 1000 x 350 x 60 mm / Preheating > 60°, interpass temperature 60° / Shielding Gas: Ar 70/He 30 / Welding Speed: Target 7. 5 ipm / Welding Position: 3 G / six layers > oscillated 49 Fronius USA / Mike Ludwig / AWS Shipbuilding Conference 2011 / xx. 201 x

…Pictorial Results Metallographic Result Back face 6 5 2 1 Front View Cap Layer 3 4 50 Fronius USA / Mike Ludwig / AWS Shipbuilding Conference 2011 / xx. 201 x

Weld Deposition Rates – 3 G-Position Narrow Gap Time Twin Aluminum Welding Number of Layer / Weld Deposition Rate lb/h Leading Electrode Wire Feed Speed m/min Trailing Electrode Wire Feed Speed in/min Welding Speed in/min 1 / ~ 14. 0 433 334 8. 6 2 / ~ 10. 4 334 236 7. 1 3 / ~ 10. 8 334 256 7. 9 4 / ~ 6. 5 197 157 7. 1 5 / ~ 10. 0 315 236 7. 1 6 / ~ 8. 6 275 197 7. 1 51 Fronius USA / Mike Ludwig / AWS Shipbuilding Conference 2011 / xx. 201 x

Conclusion / LNG aluminum alloy sphere manufacturing requires highest weld quality levels / Continuous increase in production rates requires a rise in welding process efficiency / Out-of-position single wire MIG GMAW has reached physical limits / Time Twin Tandem Welding was shifted towards being usable for out-of-position welding / Project requirements to improve quality and efficiency could be met entirely / Tailor-made welding power supply welding characteristics were used to cover the complete process range / Sophisticated welding torch engineering resolved joint design restrictions / Time Twin Process with narrow groove torch equipment proved excellent suitability for similar aluminum welding applications 52 Fronius USA / Mike Ludwig / AWS Shipbuilding Conference 2011 / xx. 201 x