| STRESS-CORROSION CRACKING (SCC) is the sudden failure of ductile material due to the presence of tensile stresses in a corrosive environment. There are three factors affecting the presence of SCC: material suitability to SCC, corrosive environment, and high tensile stresses. SCC cracks may propagate until a complete failure of the pipeline material occurs, and several incidents that led to catastrophic failure of gas pipelines due to SCC have taken place in Saudi Arabia and other countries. From those experiences, it is clear that SCC has a significant impact on the integrity of pipelines.
This paper highlights the in-line inspection of a gas pipeline using an electromagnetic acoustic transducer (EMAT) tool. It explains the experience with SCC on one of Saudi Aramco’s gas pipelines, and it also covers the inspection techniques deployed to detect this type of cracking and the repair methods. |