IIW Commission meetings in Annual Assembly Prague, Czech Republic on July 11 to 13, 2005 Meeting Notes by Alice Lau

Transcription

1 IIW Commission meetings in Annual Assembly Prague, Czech Republic on July 11 to 13, 2005 Meeting Notes by Alice Lau All papers are on the IIW website in the Working Group area of Commission XII July 11, 2005 Commission XII Chairman: Dr. Lucas 2:00pm 6:00 pm Introduction Intermediate meetings in Austria Proposed new Sub-commissions: a. Sensors & controls b. Arc welding process c. Production systems & Applications d. Underwater Engineering e. Quality & safety in welding Sub-Commission A- Sensors & Controls Chairman J.S. Smith 1. Doc: XII Upper Surface Pool Width Regulation for the Controlled Welding of Ni Based Super Alloys Conclusion: -presented a vision system to measure the weld pool accurately for Pulse GTAW -measurement is then used in the PID controlled system in order to maintain a uniform weld bead size during automated welding of Ni based super alloys Summary: -prototype system for the demonstration of an image processing technique for the reliable processing of high quality top face weld images -capable of real time operation -Uses a simple CAN based distributed controller mechanism for ease of integration -closed loop control of weld pool width for improved weld profile -Upper surface width will have an influence on the weld penetration -will work with pulsed arc -configurable for different process 2. Doc: XII Sensing & Seam Tracking of Welding line in blackingless V groove welding -Application of switch back welding to the welding line on the circumference is investigated -The seam tracking controller is redesigned to save the teaching time. The point of the beginning and estimated center are given to robot 1

2 Sub-Commission B- Arc Welding Processes 3. Doc: XII The CMT Process-A revolution in Welding Technology -This process can be combined with other processes easily -CMT- Cold Metal Transfer -Main applications: Spatter free, thin-sheet welding, arc joining steel & aluminum 4. Doc:XII Steering the heat input with the MIG process -Mixed mode shifts the process out of low energy to metal flow region -the system comes close to the conventional Mig-Pulse system. -to stay in low energy region, use large diameter wire 5. Doc.XII High speed Tandem Pulsed GMA Welding of Steel Sheets -the effect of the torch configuration, wire feed speed, and the chemical composition have been investigated. -Using 4 types of welding wires -max welding speed 2 to 3 m/min to achieve sound weld bead -uniform welds can be achieved by 5 to 15 degree push angle -inter-wire distance affect the uniformity of the weld: 9 to 12mm - Current ratio between trailing and eading:0.31 to 0.5 to achieve max welding speed 4 to 4.5 m/min 6. Doc XII Droplet Burnoff measurements on the VP-GMAW process -developed melting point measurement method to evaluate the melting behavior of Variable Polarity of GMAW process 7. XII Classification of Metal Transfer Modes in GMAW IIW Classification- 1. Free flight transfer, ( Globular, Spray, Explosive) 2. Bridging transfer, 3. Slag projected transfer To accommodate developments in power source, * process control technology, two additional classifications: 1. Controlled transfer classification 2. Extended operating mode classification Proposed IIW Classification of GMA Metal Transfer Modes A. Short circuiting, B Globular, C. Spray, D. Pulsed, E. Rotating 2

3 Sub-Commission C Production Systems and Applications 8. Doc. XII Development of Tandem Electro-Gas Arc Welding conclusion: -more efficient -applicable for thick plate of up to 80mm - good penetration and bead profile -good notch toughness at low temperature 9. Doc. XII Full Penetration Welding Process of T joints of Thick Plates without Back Gouging or backing material using high current Pulsed MAG Welding -hot cracks -welding condition -size of root face -high pulse current MAG welding without back gouging gives 30% reduction of distortion & 57% decrease in working hours July 12, 2005 Commission XII, Commission IV One day joint Workshop The Derek Russel Workshop Exploiting the High Efficiency of the Laser- Arc Hybrid Welding Process 2:00 pm to 6:00 pm Note: This is a one day workshop and I only will attend the afternoon session. In the morning, I have to attend the Commission II meeting. For other papers, please see attached agenda from Commission IV. 1. Doc. XII Laser-Arc Hybrid Welding System for Various 3D Welding Development of Coaxial Laser Welding Head -Hybrid Welding advantages: Laser, not enough leg, MIG insufficient penetration, -MIG-YAG sufficient penetration and suppress deformation. -application of MIG-YAG welding smooth surface and back with no porosity, sufficient penetration and ensure leg length -Hybrid welding heads combining arc and laser were developed to apply to the complication e.g. 3D welding S shape welding Al 2. Doc. XII Laser & Laser GMA welding (paper not yet on the website)by BIAS -CO2 Laser welding - -comparison of CO2 Laser and Fiber Laser reduce energy -Laser and Hybrid welding of pipe steel -CO2 laser beam and GMA influence of process distance -Interactions bet CO2 laser beam & GMA 3

4 -YAG laser GMA hybrid welding of extruded Al Profiles -Fiber laser GMA Hybrid welding of extruded Al Profiles 9m/min much faster but has porosity -hybrid welding of Aluminum and steel -conclusion process understanding, mature system technology, the specific requirements of the application have to be taken into account 3. Doc.-IV State of Industrial laser hybrid application in Sweden -3 main categories: automotive, mechanical construction, research and development e.g. automotive industry e.g. mechanical engineering 3 to 8mm, deformation is min -Duroc using this industrial application for welding the wagon in the train -full penetration of fillet weld -laser welding prefers some He, -process engineering: Permanova-swedish laser hybrid tool -safety is an issue fully sealed cell is required E.g. Saf2205 offshore pipe, Austenite and Ferrite in balance 4. Doc. XII Application of YAG-TIG Hybrid Process for Coil Casing (Tentative) -The application of laser arc hybrid welding process was evaluated as a manufacturing process of super-conductive coil parts - deeper penetration when the arc is made to precede in the TIG-GYAG hybrid welding -obtain same penetration depth in hybrid welding using double flux TIG -increase arc current, will increase penetration depth in the double flux TIG YAG hybrid welding. 5. Doc IV_ Yb Fibre Laser/MAG Hybrid Processing for Welding of Pipelines -describes the technical progress made throughout using Nd:YAG laser to hybrid procedures -over the past 10 yrs, laser technology has developed to use high power and efficient Yb fibre laser power -hybrid Yb fibre/mag process can be used at high speed (1.8m/min) -weld test results show strength and impact values are acceptable to current pipeline standards 6. Doc XII High Power Fibre Laser New Prospects for Laser and Laser-Hybrid Welding in shipbuilding -10 kw fibre laser used to increase efficiency -application of fibre laser is much more faster than conventional GMAW or SMAW procedures. 4

5 July 13, 2005 Commission XII Chairman: Dr. Lucas Sub-Commission C - Production Systems Chairman Y. Sugitani 1. Doc. XII Development of specialized robot system in the arc welding -a special system with one control of welder and computer instead of two controls of conventional system. -Optimize power unit for robot Sub-Commission D Underwater Engineering Chairman, I. Richardson 2. Doc.XII A flexible waveform representation for Gas Metal Arc Welding -methodology for GMA power source waveform representation -to give flexibility, tractability, and ease of operation. -two different waveform structures are described 3. Doc. XII Subsea Pipeline repair-deverless GMA Welding using a fillet welded sleeve -hyperbaric GMA welding procedure development using a fillet weld sleeve for pipeline repair 180 to 250mm depth range -customized MCAW consumables has been developed for excellent toughness for X65 sleeve remote pipeline repair system 4. Doc.XII Some Aspects of underwater Engineering Ministry of Defense 1995 to date -defined underwater engineering, cost saving -only one of six welding consumables (hydroweld F.S.) pass all the requirements of Ministry of Defense -FCAW system: Breakdown of time to weld is about ½ of the time comparing to MMA (Manual Metal Arc) -welding and epoxy adhesive provided the highest joint strength 19MPa -Polymeric system to repair of structures in water try bonding trials 5. Doc. XII Wet underwater welding a real alternative -Ni consumables -when a submarine reaches the end of its life, it goes under DDLP, very expensive -why weld underwater, dry docking is expensive -wet welding procedure is developed and achieved good shearing strength, hydroweld 6013 is used, welder skills is very important 5