|The use of longitudinal seam-welded line pipe produced in continuous welding lines has increased in recent years. These
pipes must apply to different standards, like API, ISO, DnV, etc. The trends are that the wall thicknesses of the pipes have
increased and the materials used have set new demands on the heat treating process. Understanding the dynamics of the seam
normalizing process and processes with intermediate quenching, during heating and cooling is, therefore, important in order
to meet the different requirements.|
|EFD Induction has unveiled a new control system for normalizing pipe weld seams to API standards. Per H. Ødesneltvedt, one of the R&D engineers involved in the project, explains some of the system’s features and benefits.
|In the production of welded pipes according to API standards, a normalization of the weld and heat affected zone (HAZ) is required. The weld of thick-walled tubes shows an hour-glass shaped HAZ caused by the ”corner effect” in the weld Vee. |