Visualization of Damages of the Main Pipelines Using Cyclic Hydro Testing

The fracture of the pipelines is often occurred in the vicinity of weld joints. It is important to consider the scattered damages in the bulk material and their effect on the mechanical properties. These damages could be visualized by hydro testing of long-term exploited pipes with following fractography investigation of the obtained fracture surfaces. The bulk damages of 10G2C1 steel after 45 years of operation on the pipeline were analyzed using mechanical characteristics of metal and fractography features of fracture. Strength and ductility characteristics, impact toughness of the exploited steel (as a base metal) and metal from different zones of longitudinal weld joint on the pipe were analyzed.