CORROSION-ASSISTED CRACKING IN LIFE OPTIMIZATION OF POWER-PLANT COMPONENTS

Corrosion assisted cracking becomes important for ageing plant compone nts which are subjected to loading while in contact with an aggressive environment. Fracture mechanics test techniques and data reduction me thods have been shown to be useful to predict component behaviour; nev ertheless, it is necessary to further investigate the validity of such methods when environmental effects are present. In this case, in part icular for low-allow steels used in power generation plants, time-depe ndent effects are important and strain rate is a key parameter. This p aper, making reference to the results of a cooperation between CISE an d ENEL to study the behaviour of materials for power generation plants , presents a procedure recommended for preventing and controlling envi ronmentally assisted cracking in ageing components. Results of researc h programmes will be shown, where a contribution to the solution of ac tual problems is given.