Acoustic Emission Testing (AT) for the detection of corrosion attack on ships (oil tankers)

摘要

The transportation of oil, which is the most important raw material for the energy production, includes most time crossing of the sea, mainly with oil tankers. This transportation can be very dangerous for the environment, how we learned it in the last decades. Some of the old oil tankers have had accidents with an enormous mass of oil spillage into the sea and fatal consequences for Flora and Fauna, in specific I will remember on the accidents of Prestige and Erika. Beside human errors the degradation of the structural integrity by corrosion attack was the most important reason. For better controls of these tankers an Austrian, German and Polish consortium started 2002 an EC founded R&D project for "Detection and discrimination of corrosion attack on ships (crude oil tankers) with Acoustic Emission (AE)". The intention of this project was to develop a discontinuous spot testing and permanent installed system. Both systems shall detect corrosion attack on oil tankers in-time and give the ships owners as well the port authority a fast and reliable tool to validate the momentous status of tankers. During the last years the consortium has done extensive research works about the corrosion process and its effect on the emitted Acoustic Emission. It was possible to distinguish meaningful corrosion noise from disturb noise, coming from sea and structure itself. After development of intrinsically safe (Ex-proof) sensors, for both systems tests on ships were performed. Consequently the validation of the systems was done on Navy tanker "Baltyk" and a commercially used oil tanker "Icarus III". During these tests we could proof, that the permanent systems is able to check during the most service conditions and the spot testing has the capability to check and validate to corrosion status of the structure in harbour or on anchor place.