How to improve the toughness at low temperature of the longitudinal weld seams of pipes with w.t. < 12, 7 mm

摘要

High input welding processes are used extensively in linepipe industries for cost savings resulting from greater productivity. During these processes, the heat affected zone (HAZ) as well as the weld metal (WM) of longitudinal weld seam experiences a risk of austenite grain coarsening and deterioration of HAZ toughness. This is also true for the weld metal because the re-affected zone becomes more important with the reduced wall thickness of the pipe.