| 摘要 |
Welded drill pipes for application in the civil engineering and relative procedure for the elimination of the internal flash. The pipes, manufactured by friction welding of the sections of the pipe and the tool joints, are characterized by the elimination of the internal flash (coming out from this welded joint) which fills a proper cavity. The advantages of the new product and of the process of manufacturing are the elimination of the fluid-dynamic troubles inside the pipe, caused by the inner flash, and the elimination of the crack initiations due to fatigue-stress in the welded joint. |
