A new friction-welding process for pipeline girth welding: weldability of micro-alloyed high strength pipeline steels

摘要

An innovative welding method for fully automatic joining of pipelines has been developed and is a variant of thenconventional friction-welding process. A rotating intermediate ring is used to generate the heat necessary to create thenweld. The working principles of the welding process are described. The weldability of the micro-alloyed high strengthnAPI 5L X65 pipeline steel was experimentally investigated, and it was found that the new welding process is suitable fornjoining this material. When welding with a sufficiently low heat input, a high weld quality is obtained and under thesencircumstances the weld strength, ductility, and impact toughness are high and meet the requirements of the commonlyusednstandard EN 12732 for joining pipes