J. Rostami - Depertment of mechanical and Aerospace Engineering, Science and Research Branch, Islamic Azad University, Tehran, Iran
M.S. Safizadeh - School of Mechanical Engineering, Iran University of Science and Technology, Tehran, Iran

Corrosion in fuel and gas pipelines is a critical issue since it can cause leakage of fuel and sometimes explosion which leads to catastrophic disaster. Therefore non-destructive test of these structures for detecting defects particularly wall thinning is of vital importance. In whole testing of pipelines, elbow region needs more attention because of the existence of residual stresses and also turbulence flaw of fluid that both aggravate the corrosion and finally failure. During the past decade, utilizing ultrasonic guided waves for flaw detection in pipelines has drawn a lot of attention but the use of guided waves in pipe elbow region needs more research to be a more practical method. In this paper, the application of ultrasonic guided waves for detecting corrosion in pipe elbow region was experimentally investigated. Three 20 mm width notches with different depth- 30%, 50% and 70 % pipe wall thickness were milled on 6 inch pipe elbow as artificial corrosion defects. These defects were successfully detected via longitudinal mode of ultrasonic guided waves.

corrosion detection, guided waves, non-destructive tests, ultrasonic