Ultrasonic Testing Method Based on Signals′ Phase Changes for the Bonding Quality of Coated Layer on Pipeline

This paper analyzes the ultrasonic testing signals phase positions of coated layer on pipeline,and shows the internal relations between the bonding quality of coated anticorrosive layer and phase changes of pulse-echo signals′.Then some tests were made on coated anticorrosive layer specimen using the ultrasonic pulse-echo testing method.The results show that the phase changes of pulse-echo signals can be used to evaluate the bonding quality and the types of defects existing in the coated anticorrosive layer on pipeline.