Weldability of micro-alloyed high-strength pipeline steels using a new friction welding variant

Abstract

An innovative welding method for fully automatic joining of pipelines has been developed. Theproposed welding procedure is a variant of the conventional friction welding process. A rotatingintermediate ring is used to generate heat necessary to realise the weld. The working principles of thewelding process are described. The weldability of the micro-alloyed high-strength pipeline steel API-5L X65is experimentally investigated. It was found that the new welding process is suitable for joining this material.When welding with a sufficiently low heat input, a high weld quality is obtained. Under these circumstancesthe weld strength, ductility and impact toughness are high and fulfil the requirements of the commonly usedstandard EN 12732 for joining pipes.