Failure Analysis of ERW Seam Weld Pipeline in Internal Pressure

Fracture failure behavior of the electric resistance welding (ERW) seam weld of Φ355.6×10.3 mm L360 in high internal pressure was investigated in this paper. The mechanical, metallurgical and fractographic characteristics were studied to clarify the reason of fracture failure for the ERW seam weld. The experimental results showed that the impurity and flaw of weld area were the main factors for the failure of ERW seam weld in high internal pressure. The impurity and flaw in welds had great effects on the mechanical characteristics of ERW. The approaches to ensure the integrity of the pipeline in service were proposed.