STRESS-CORROSION CRACK COALESCENCE

The stress corrosion cracking of a pipeline steel exposed to a carbonate-bicarbonate solution has been studied under various loading conditions, particularly those involving a relatively small component of fluctuating stress applied for various times. It is shown that the coalescence of stress corrosion cracks plays a critical role in the overall growth process and that failure times can be accounted for only if coalescence is taken into account. It is likely that the concept will be applicable to other systems that display stress corrosion cracking and there is a need for similar studies in such systems if the realistic prediction of the remaining lifetimes of cracked structures is to be achieved.