Obtaining residual stress along weld beads by means of analytical and experimental methods |
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| Authors: | YG Rodriguez JB Sola F Gil J Rivalta |
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| Affiliation: | 1. Centre of Welding Investigations, Faculty of Mechanical Engineering , Marta Abreu de Las Villas Central University , Villa Clara, Cuba;2. Mechanical Plant , “Aguilar Noriega Factory” , Santa Clara, Villa Clara, Cuba |
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| Abstract: | In CO2 arc welding of solid wire, metal transfer phenomena and spatter generation are investigated with rectangular pulse current, and a low spatter CO2 arc welding process with high frequency pulse current is developed. The optimal conditions of high frequency pulse CO2 arc welding are in the range of peak current: 450–550 A and pulse frequency: 450–750 Hz. These high frequency pulse currents have the effect of droplet oscillation due to resonance between applied pulse frequency and the natural frequency of the droplet. The droplet is transferred consistently every 9–11 pulses and the average interval of metal transfer is about 16 ms which is reduced to half that of conventional CO2 arc welding. This average droplet weight is 34 mg, showing a large reduction in comparison with that of the conventional method. As a result, total spatter weight is reduced by 70% in comparison with the conventional method, and especially, large spatters more than 0.5 mm in diameter are reduced from 1.5 to 0.2 g/min. |
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| Keywords: | CO2 gas shielded arc welding spatter welding wire high frequency pulse current |
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