Accelerated crack growth experiments of SS304H for dry storage canister in substitute ocean water – Effect of temperature. (June 2020)

• Record Type: Journal Article
• Authors: Tjayadi, Leonardi; Kumar, Nilesh; Murty, Korukonda L
• Is Part Of: Materials today communications. Volume 23(2020)
• Publication Date: 2020-06
• Subjects: Dry storage canister -- Chloride induced stress corrosion cracking -- Austenitic stainless steel -- SS304H -- Direct current potential drop -- Fracture mechanics; Materials science -- Periodicals; 620.11
• DOI: 10.1016/j.mtcomm.2020.100929
• Languages: English
• ISSNs: 2352-4928

Abstract

Highlights: Fracture mechanics based stress corrosion cracking (SCC) study of SS304H. Wedge opening loading type specimen used for SCC study. Direct-current potential drop technique used for crack growth measurement. Hydrogen diffusion responsible for crack propagation. Sensitized specimens exhibited intergranular crack propagation. Abstract: Spent nuclear fuels (SNFs) are expected to be stored in dry storage canisters (DSCs) for much longer time than earlier anticipated due to a lack of permanent deep geological repository. As a result, DSCs located in marine environment may undergo chloride induced stress corrosion cracking (SCC) during long-term storage of SNFs. We report here the effect of test temperature on accelerated crack growth experiments carried out on sensitized austenitic stainless steel SS304H in substitute ocean water using fracture mechanics approach. Wedge-opening loading specimens were selected for measurement of crack growth rates using direct-current potential drop technique. Average crack growth rates of 0.975 × 10 −10 ± 9.528 × 10 -12, 3.258 × 10 −10 ± 9.551 × 10 -11 and 1.580 × 10 -9 ± 2.593 × 10 −10 m/s were obtained for 22, 37 and 60 °C, respectively resulting in an activation energy of 60.9 kJ/mol corresponding to diffusion of hydrogen in steel. Intergranular crack propagation was noted along with formation of chromium-rich carbide precipitates at grain boundaries.