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Stress Corrosion Cracking (SCC) tests were carried out on C(T) notched specimens of pipeline steel,
using two different methodologies: load control and slow strain rate. The tested material is a pipeline
steel with perlitic-ferritic structure. Tests were carried out both in air and in acqueous environment,
simulating the environment present under a disbonded coating.
The aim of the work is essentially to compare data of crack grow velocities obtained with the two methods
above mentioned in order to obtain a better understanding of the material behavior. The effects of strain
rate and loading methodology have been discussed under the hipothesis that crack propagation in the
examined environment is due to hydrogen related mechanism. Results have been correlated with optical
(LM) and electronic microscopy (SEM) examination of the fracture surface. Prelimanary results do
indicate that Load Control Methodology (in respect to Slow Strain Rate) offers a better separation
between mechanical and environmental components both concourring to crack grow. Integration of the
two techniques allows a better understanding of the material behavior.