Pratyush Mishra

Characterization of Sub-surface Damage During the Early Stage of Stress Corrosion Cracking by Nano Indentation

Stress Corrosion Cracking (SCC) is a cracking process observed in metals under tensile stress and corrosive environment. It has been reported as one of the major failure modes in high strength steel pipelines over few decades. This study aims to characterize sub-surface damage, which leads to near surface mechanical property changes during the initiation stage of SCC. The quasi-static and dynamic nano indentation technique, were utilized to resolve the mechanical property variation in the near-surface region. The measurements indicated significant softening and modulus reduction near the grain boundaries. Such findings could further elucidate the underlying deformation mechanisms during the early stage of SCC as a function of degradation level.