Non-destructive evaluation of multi-layer piping using laser ultrasonic technique

Abstract

Recently, multilayer piping has been used widely. Multilayer piping has excellent durability and corrosion resistance. An effective means for quality maintenance of multilayer piping is the laser ultrasonic technique for checking the state of adhesion of the vinyl chloride layer and the steel layer of multilayer piping. The wave is refracted at the interface between the steel layer and the vinyl chloride layer based on the wave motion principle. The arrival time of the reflection wave was calculated and confirmed by measurements. If measurement of piping under high temperature becomes possible, the effectiveness of the non-destructive testing technology by the laser ultrasonic technique can be expected, enabling the production of higher reliability and quality of multilayer piping. © 2012 The Japan Institute of Metals.