Abstract
Despite being a method of choice for the detection of stress corrosion cracking (SCC) on carbon steel surfaces, eddy current array (ECA) technologies are still rarely being used for measuring the depth of these cracks. Phased array ultrasonic testing (PAUT) remains the technique of choice. While offering a high level of accuracy on crack depth, PAUT is still relatively slow and dependent of the operator carrying out the inspection. There is currently a strong need in the pipeline industry for a technology that would ally the speed and ease of use of ECA with the depth sizing capabilities of PAUT. This paper presents the most recent advances of eddy current array technologies for the depth sizing of SCC in carbon steel pipelines. Several field trials have been conducted to validate the performance and accuracy of tangential eddy current array (TECA) through comparisons with controlled grinding of the SCC indications. These results show that the main advantages of ECA over PAUT reside in the short amount of time required to locate and size the deepest crack within a colony of SCC, in addition to being more user-friendly and less operator dependent. Ultimately, the field results presented in this paper show how TECA could transform the work of technicians in the digs, and above all, ensure a more reliable management of SCC related threats in pipelines.
