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In a quest to vet UNS S32205 as a potential structural material to serve moderate-to-high temperature operations of NPP auxiliary components, the DL-EPR test was exploited. A bifronted scheme comprised of 650 and 850 °C discrete treatments intended to explore progressive eutectoid decomposition and degree-of-sensitization (DoS) scenarios was adopted. The nuance witnessed with yet another dual approach—the Cihal- and image processing (IP)-normalized signal landscape—was rationalized through its attribution to culprit microstructures. This was sought, inter alia, in the vicinity of grain boundaries and σ-phase inclusions by virtue of postmortem FESEM, STEM-EDX, HRTEM SAED and XRD ascertainment. Discernable reactivation-kinetics resurgence was believed to mark the onset of deleterious σ-phase dissolution. This only came into fruition with longer ageing times (8–17 h) at 650 °C and succumbed to prematurely (1 h), and at DC biases more cathodic than −0.25 VAg/AgCl with the 850 °C counterpart. Opportune corroboration was offered in ir/ia breakaway for the respective conditions, which was unveiled to be particularly pre-emptive (5 h) with IP- vs. Cihal-normalized peers (8 h) related to the 650 °C condition. Meanwhile, the 850 °C condition endured a similar surge after as little as 1 h of ageing across the board, which hints at concomitant sigma-phase culpability. [ABSTRACT FROM AUTHOR]

The paper describes an experimental study concerning the influence of major environmental parameters (temperature, chloride, carbon dioxide, and oxygen) on the corrosion behavior of 90/10 Cu–Ni alloys widely used for heat-transfer tubes. Electrochemical techniques have been used to investigate the corrosion behavior of 90/10 Cu–Ni alloys in aerated 3.5% NaCl solutions, at temperatures of 25, 50, and 80°C with and without the injection of carbon dioxide. The results have revealed increases in chloride corrosion rates of the 90/10 Cu–Ni alloy with temperature and decreases with CO2presence. Tests performed in aerated chloride–CO2solutions have shown higher corrosion rates relative to those conducted in deaerated chloride solutions saturated with CO2species. The surface morphology of polarized specimens in chloride solutions with and without CO2presence has shown a susceptibility to pitting attack. Pit characteristics have been found to be highly influenced by CO2presence. [ABSTRACT FROM AUTHOR]