El presente artículo pretende dar respuesta a una demanda tecnológica del astillero TECNAO SRL, ubicado en lazona de San Fernando en la provincia de Buenos Aires, Argentina, este se dedica a la fabricación de barcos de bajo porte, fabricados principalmente de aluminio. El problema detectado consiste en la dificultad que se presenta en el proceso de fabricación de las naves, en lo referente al posicionamiento de las planchas de aluminio a soldar, que se posicionan mediante un punteo previo. En la actualidad, dicha actividad se realiza mediante procesos de soldadura tradicionales MIG o TIG, lo que obliga a trasladar las torchas a lo largo de todo el barco y a la necesidad de contar con personal altamente calificado para realizar esta tarea, lo que impacta fuertemente en el costo y en la competitividad del sector, además de los problemas de distorsión de las planchas por efecto de las altas temperaturas asociadas a los procesos utilizados. El presente trabajo describe los estudios realizados tendientes al diseño de un equipo portátil de soldadura de punto por fricción-agitación (FSSW)de aplicación en la industria naval. Se evaluóla incorporación FSSWcon una herramienta autónoma. La herramienta permitióel punteo de la estructura sin la necesidad del movimiento de torchas a lo largo de todo el barco, se presentó una complejidad adicional,soldar espesores mayores a3mm, esto resultorelevante en la investigación

The present work aims to respond to a technological demand from the TECNAO SRL shipyard, located in the San Fernando area in the province of Buenos Aires, Argentina, which is dedicated to the manufacture of small ships, mainly made of aluminum. The problem detected consists of the difficulty posed by the manufacturing process of the ships, especially with regard to the positioning of the aluminum plates to be welded, which are positioned by means of a previous spotting. Currently, this activity is carried out using traditional MIG or TIG welding processes, which forces the torches to be moved throughout the entire ship and the need to have highly qualified personnel to carry out this task, which has a strong impact on the cost and competitiveness of the sector, in addition to the problems of distortion of the plates due to the effect of the high temperatures associated with the processes used. The solution to the problem raised consists of a technological advance incorporating in the Argentine small-scale naval industry an innovative process that is the use of the friction-stirring point welding process, in English Friction Spot Stir Welding (FSSW). Another important advance with respect to the state of the art of the manufacture of small vessels in the Argentine naval industry is to be able to do it with an autonomous tool in order to allow the plucking of the structure without the need for the movement of torches along the the whole ship. An additional complexity that is an important advance in the state of the art is also the ability to weld thicknesses greater than 3mm. The present work describes the studies carried out aimed at the design of a portable FSSW equipment for application in the Naval Industry.

Friction stir spot welding (FSSW) is a novel process of metal joining. In the present work, the authors analysed the possibility of using this process to solve current problems in shipbuilding industry regarding small vessels by replacing the current arc welding techniques with the aforementioned process. Numerical simulation was carried out by the multiple purpose solver framework for Finite Element Method with a novel modelling approach. The problem was solved using a coupled mechanics system of equations in an axisymmetric continuum where material velocities were calculated in three dimensions, coupled with pressure and thermal fields. The heat source was calculated as a consequence of internal friction dissipation only. Two boundary conditions were analysed, adiabatic and with heat dissipation. Experimental welding tests were performed using a milling machine. Comparison between numerical modelling results and experimental FSSW testing results was done and analysed in detail.