Welding plays a key role in the energy sector for the construction of pipelines used in the transport of oil, natural gas and biofuels. Most welding applications destined to Brazilian constructions bring little technological intervention, which would in fact add more productive value and better quality indices. Given this scenario and as an attempt to change this paradigm, the present work presents an approach that aims at the implementation of a technology developed nationally and envisaged for pipe root welding, entitled Controlled Short Circuiting (CCC). The performance of the CCC version was verified in the root welding of different pipes with varied diameters and wall thicknesses. All the trials for validation of procedures were performed with orbital mechanized system in API 5L X 70 and API 5L grade B pipes, with "U" groove profile, without the use of weld pool backing. These tests were simulated in situations similar to those found in the field in the construction of pipelines. The results obtained showed the reliability of the system as a whole, which performed root pass welds with great robustness, quality and repeatability, meeting specific standards requirements for this segment.
SARTORI. F.; SILVA. R. H. G. Performance of the MIG / MAG - CCC (Controlled Short Circuiting) Version in the Root Welding in Pipes with Mechanized System. Brazilian Petroleum, Gas and Biofuels Institute - IBP. Rio Pipeline Conference & Exhibition, Rio de Janeiro, 2017.