Determination of residual welding stresses in multipass joints API 5L X80 steel

This study evaluated the residual stresses in welded joints of API 5L X80 steel. They were used three different welding processes for the execution of welding (SMAW, GTAW and FCAW-self-protecting). Four welded joints were obtained by varying consumable and welding parameters. The Residual stresses were assessed by x-ray diffraction in the upper and bottom regions of the plates. In the upper regions was found that, by employing similar heat input, but with higher current and welding speed, the residual stresses are more compressive. It was found that the use of higher currents implies more compressive residual stresses along the Weld Metal (WM) on the upper surface. In the case of the bottom region, the residual stresses were more attractive in WM with the use of higher heat input.. (author)