Patent ID: 8245903
Filing Date: 2012-08-21
Classification: B23K

Abstract:
1. A method of joining thin-walled jackets by fusion welding, the method comprising the steps of sequentially: preparing end faces of the jackets by plastically deforming and upsetting microprojections thereon and thereby forming the metal of the upset microprojections into annular beads on inner surfaces of the respective jackets, abutting the inner surfaces of the end faces including the annular beads while centering the jackets on each other relative to their external diameters, spot welding the end faces together in a plane where the end faces abut, joining the spot-welded end faces with a continuous main weld having a width equal to between 4δ and 6δ, δ being the thickness in mm of the wall of the jacket, and extracting heat from the welded jackets starting at a distance not exceeding 8δ from a joint center line where the end faces abut.