Parameter optimisation for automatic pipeline girth welding using a new friction welding method

A new welding method for fully automatic welding of pipelines has been developed. The proposed welding procedure, called Friex, is a new variant of the well-known friction welding process. An intermediate ring is rotated in between the pipes to be welded to generate the heat necessary to realise the weld. In the first part of this paper, the working principles of the Friex welding process are briefly described. Following, the influence of the rotation speed on the weld properties is discussed for welding 3 in. pipes in the pipeline steel API-5L X52. Two normalised fine-grained steels were used for the welding ring. The optimisation of the thickness of the welding ring is discussed.