Hybrid Welding of AA5754-H111 Alloy Using a Fiber Laser

2012 ◽  
Vol 628 ◽  
pp. 193-198 ◽  
Author(s):  
Giuseppe Casalino ◽  
Sabina Campanelli ◽  
Antonio D. Ludovico

The new generation of high power fiber lasers presents several benefits for industrial application. Nevertheless, due to the small spot size of the laser, the fiber laser has difficulties in some welding applications. These shortcomings can be overcome by laser-arc hybrid welding technique such as laser-gas metal arc welding or laser-gas tungsten arc welding. In this work, a high power fiber laser was coupled to an arc welder and the AA5754-H111 magnesium aluminum alloy was welded. The trials were carried out using laser leading configuration. A new generation of high power fiber laser was used. The experimental trials included process parameters such as laser power, welding speed and arc current. Microstructure, microhardness and weld appearance were analyzed. The experimental results showed that laser leading configuration produces full penetration for some welding parameters. The obtained results worth a larger investigation based on the experimental design technique.

Author(s):  
Ian D. Harris ◽  
Mark I. Norfolk

Despite significant investment, one-shot welding and power beam processes have not been very successful in achieving real benefits in pipeline construction. The most promising of the newer and more innovative welding processes is the hybrid Laser/arc welding process (HLAW), which can complete 5G welds, assure weld soundness, material properties, and an acceptable geometric profile. The combination of new lasers and pulsed gas metal arc welding (GMAW-P) power source technologies have led to important innovations in the HLAW process that have been shown to increase the travel speed for successful root pass welding. In particular, high power Yb fiber lasers with high efficiency (25% compared with 3% for a Nd:YAG laser) allow a 10kW laser to be built the size of a refrigerator. This allows for previously unheard of portability and power levels for use outside the laboratory and on the pipeline right-of-way. The objective was to develop and apply an innovative HLAW system for mechanized welding of high strength, high integrity, pipelines and develop 5G welding procedures for X80 and X100 pipe, including mechanical testing to API 1104. The main goal of a cost-matched JIP was to develop a prototype hybrid high power Yb fiber laser and GMAW head based on a commercially available bug and band system (Figure 1). Under the DOT project, the subject of this paper, innovative technologies for pipeline girth welding were developed. External hybrid root pass welding techniques were developed for variations of laser power (4–10 kW) and root face thickness (4–8 mm) as this has the greatest potential to meet existing pipeline integrity requirements and facilitate the use of new high power Yb fiber lasers for high speed HLAW of pipe root passes. Following the integration of the Yb fiber laser and GMAW head onto a commercially available bug and band system (CRC-Evans P450) the system was used to achieve full penetration welds with a 4 mm root at a travel speed of 2.3 m/min. The root welds were made in a “double down” configuration using laser powers up to 10kW and travel speeds up to 3 m/min. The final objective of the project is to demonstrate the hybrid LBW/GMAW system under field conditions.


2013 ◽  
Vol 339 ◽  
pp. 700-705 ◽  
Author(s):  
Victor Lopez ◽  
Arturo Reyes ◽  
Patricia Zambrano

The effect of heat input on the transformation of retained austenite steels transformation induced plasticity (TRIP) was investigated in the heat affected zone (HAZ) of the Gas Metal Arc Welding GMAW process. The determination of retained austenite of the HAZ is important in optimizing the welding parameters when welding TRIP steels, because this will greatly influence the mechanical properties of the welding joint due to the transformation of residual austenite into martensite due to work hardening. Coupons were welded with high and low heat input for investigating the austenite transformation of the base metal due to heat applied by the welding process and was evaluated by optical microscopy and the method of X-Ray Diffraction (XRD). Data analyzed shows that the volume fraction of retained austenite in the HAZ increases with the heat input applied by the welding process, being greater as the heat input increase and decrease the cooling rate, this due to variation in the travel speed of the weld path.


Author(s):  
Cole Homer ◽  
Epstein Seymour ◽  
Peace Jon

Fabrication and repair of aluminum components and structures commonly involves the use of electric arc welding. The interaction of the arc and the metal being welded generates ultraviolet radiation, metallic oxides, fumes, and gases. Aluminum is seldom used as the pure metal but is often alloyed with other metals to improve strength and other physical properties. Therefore, the exact composition of any emissions will depend on the welding process and the particular aluminum alloy being welded. To quantify such emissions, The Aluminum Association sponsored several studies to characterize arc welding emissions by the gas metal arc welding (GMAW) and gas tungsten arc welding (GTAW) processes for various combinations of base and filler alloys. In all cases, the tests were conducted under conditions that could be found in a production weld shop without forced ventilation. The concentrations of each analyte that a welder could be exposed to were greatly affected by the welding process, the composition of the base and filler alloys, the position of the welder, and the welding helmet. The results obtained can be used by employers to identify and control potential hazards associated with the welding of aluminum alloys and can provide the basis for hazard communication to employees involved in the welding of these alloys.


Procedia CIRP ◽  
2016 ◽  
Vol 40 ◽  
pp. 642-647 ◽  
Author(s):  
Gunther Sproesser ◽  
Andreas Pittner ◽  
Michael Rethmeier

Author(s):  
Jaber Jamal ◽  
Basil Darras ◽  
Hossam Kishawy

The concept of “sustainability” has recently risen to take the old concept of going “green” further. This article presents general methodologies for sustainability assessments. These were then adapted to measure and assess the sustainability of welding processes through building a complete framework, to determine the best welding process for a particular application. To apply this methodology, data about the welding processes would be collected and segregated into four categories: environmental impact, economic impact, social impact, and physical performance. The performance of each category would then be aggregated into a single sustainability score. To demonstrate the capability of this methodology, case studies of three different welding processes were performed. Friction stir welding obtained the highest overall sustainability score compared to gas tungsten arc welding and gas metal arc welding.


2019 ◽  
Vol 269 ◽  
pp. 06002
Author(s):  
Salina Saidin ◽  
Dahia Andud ◽  
Yupiter H. P. Manurung ◽  
Muhd. Faiz Mat ◽  
Noridzwan Nordin ◽  
...  

This paper deals with a comprehensive investigation of fatigue life enhancement on semiautomated Gas Metal Arc Welding (GTAW) butt weld joint which is found almost everywhere in Malaysia welding structure steel sectors. The selected material in this study was high strength low alloy steel S460G2+M commonly used extremely in steel structure due to its outstanding mechanical properties. In this investigation, the method for joining the butt weld was conducted by unprofessional welder using semi-automated GMAW. At first, suitable welding parameters were identified and formulated into welding procedure specification (WPS) qualification conforming to AWS D1.1 standard. The test specimens were prepared and tested to ensure the welding quality. Further, the HFMI using Pneumatic Impact Treatment (PIT) technique were applied at the weld toe of the butt weld as tool for fatigue life enhancement. To investigate the influence of HFMI/PIT on the fatigue strength, the specimens were undergone fatigue test using universal fatigue machine using a constant amplitude loading. Finally, the comparison of the fatigue strength of as welded and treated specimens to indicate the beneficial influence of the treatment. Yes, the conduction by unprofessional welder using semi-automatic GMAW, the findings showed the improvement of fatigue strength and slope of S-N curves. In addition, the fracture location of test specimen shows physically affected by shifting from critical weld transition to base metal. The tensile test and hardness value also showed a slight difference as compared to untreated specimens.


2011 ◽  
Vol 57 (Special Issue) ◽  
pp. S50-S56 ◽  
Author(s):  
P. Čičo ◽  
D. Kalincová ◽  
M. Kotus

This paper is focused on the analysis of the welding technology influence on the microstructure production and quality of the welded joint. Steel of class STN 41 1375 was selected for the experiment, the samples were welded by arc welding including two methods: a manual one by coated electrode and gas metal arc welding method. Macro and microstructural analyses of the experimental welded joints confirmed that the welding parameters affected the welded joint structure in terms of the grain size and character of the structural phase.


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