Corrosion Evaluation of Glass Fiber Reinforced Plastic (GFRP) Tanks Pressure Vessels Using Acoustic Emission Technology

摘要

IREINE project (Innovation for the Reliability of Industrial Equipment) is a study conducted by Arkema, Technip and UTC to develop an innovative NDT (Non Destructive Testing) methodology using acoustic emission (AE) to evaluate active corrosion on Glass Fiber Reinforced Plastic (GFRP) structures. GFRP equipment is widely used in the chemical industry, especially for storage of corrosive products. Failure of such equipment can have important impacts on people safety, environment and production matters. Hence, it is essential to have a technique to ensure reliable detection of damages. The experimental work presented in this paper was aimed at investigating the ability of AE technology for evaluation of corrosion phenomena in GFRP structures. This paper describes the experimental program including field experience on full scale tanks, laboratory results and analysis of the dissection of tank structure. Corrosion tests have been performed on GFRP specimen in laboratory. Corrosive environments are used like concentrated hydrochloric acid which is known to react with E-glass fibers. Acoustic emission results reveal different corrosion modes of glass fibers in HCl solutions. This is in agreement with physicochemical analysis. For the field applications, full scale GFRP equipment was instrumented with a range of AE sensors. The equipment is used for storage or process of corrosive chemicals. When this corrosive content comes in contact with the GFRP wall, via some failure of the corrosion barrier, this could lead to chemical degradation of the composite. To detect such phenomenon, two approaches were adopted: passive monitoring to detect active corrosion (equipment filled in with the service fluid) and AE monitoring during a proof test (according to ASTM E1067 standard). To correlate these AE measurements, the tanks were visually inspected and dissected. The AE results on field were also correlated with AE results in laboratory.