Stress corrosion assisted collapse in flat tensile specimens of high-strength structural steel

High-strength steel bars used in construction provide versatile solutions for meeting the modern criteria of sustainability and resilience required in structural engineering, through a sensitivity to assisted cracking places structural integrity at risk and limits the potential applications. One of the bar types commercially available, though less used due to this risk, are made of martensitic steel but recent improvements incorporated to their fabrication led to a randomly oriented lath-martensite microstructure that reduces their brittleness. The objective of the present research was to determine the effect of this martensitic microstructure on bar behavior regarding stress corrosion cracking. In this view, various slow-rate tensile tests have been carried out in an environment that favors hydrogen-assisted cracking and allows subcritical cracking micro-mechanisms to be identified and correlated to the fracture behavior of the bars. (c) 2022 The Authors. Published by Elsevier B.V.