The oil and gas sector have great importance in Brazilian economy due to the high demand of the country's energy matrix. The most advantageous alternative for the flow of oil-derived fluids is the use of pipelines. However, one of the main challenges for the construction of these flow lines is the way that the pipes produced by special materials are joined. Currently, in the Brazilian scenario the execution of the welding process, for stainless steel and nickel-based alloys consists mostly of manual applications, becoming hard the increase in welded joints productivity and repeatability. Therefore, the automation of this step allows several advances such as more reliable results, lower costs and healthier condition for welders. Therefore, experimental tests were carried out in a 304L stainless steel pipe laid out at 5G position. The samples were welded by GTAW with dynamic wire feeding process, using a robotic manipulator in two steps of 180º in vertical down progression. The welding parameters obtained are discussed and the puddle behavior during the root pass was online monitored by videography. It was possible to reach high welding speeds in the root pass, around 50 cm/min in a keyhole mode. The wire’s movement contributed to reach great process stability and robustness, for all joint filling passes. The macrographs and x-ray analysis did not indicate discontinuities as porosity and lack of fusion.
Keywords: Spools welding; TIP TIG; stainless steel pipe welding; Root pass.
RIFFEL. K.C., SILVA. R.H.G., DIRENE FILHO. H., ELIAS. B.O., MELLER. R.N. Development of Welding Technique Based on Automated GTAW with Dynamic Feeding for 304l Stainless Steel Pipe. Brazilian Petroleum, Gas and Biofuels Institute - IBP. Rio Pipeline Conference and Exhibition 2019, Rio de Janeiro, 2019.