This investigation is focused on the evaluation of stress corrosion cracking (SCC), localized corrosion, and hydrogen embrittlement (HE) susceptibility of martensitic Alloy EP-823 in neutral and acidic solutions at ambient and elevated temperatures. While no failures were observed in smooth specimens in the neutral solution, failures were noticed in the 90 C acidic solution at constant-load (CL) leading to a threshold stress ( th) of 102 ksi. The presence of a notch reduced the th value to 91 ksi in a similar environment. The ductility (%El and %RA), time-to-failure (TTF), and true failure...