The purpose of the proposed project is to establish the interrelationship between polymer oxidation, due to both heat and light and biodegradation by defining the parameters involved scientifically.
Measurements on an operating header have been carried out on two vessel/tube intersection geometries. Development of a residual stress mapping system using Barkhausen noise analysis (BNA) and ultrasonic testing (UT) to evaluate high thermal stress locations and determination and modelling of creep and growth behaviour and thermomechanical finite element analysis of operating components have been finished.
Development of an online crack detection and off line nondestructive evaluation method for linear surface crack detection and sizing are also finishing. Development is now centred on field demonstration.
The main conclusions are as follows:
the UT technique for inner cracking detection and sizing has shown good results;
new equations for constitutive laws on creep and creep fatigue have been developed together with a big data bank for the 1 chromium 0.5 molybdenum material;
the algorithm for calculation of crack initiation was implemented in a software code;
a specificaton of the condition analysis system was produced in paper form;
further development is required on probes capable of working inside a boiler.
The system will comprise a validated computer-based lifetime monitoring system with integrated on-line and off-line analytical/NDE features utilising sophisticated inelastic modelling schemes to address crack initiation and propagation at component weldings.
KT22 7SA Leatherhead, Surrey