Role of irradiation and irradiation defects on the oxidation first stages of a 316L austenitic stainless steel

Abstract

The role of irradiation and irradiation defects on the oxidation first stages of 316 L alloy was investigated. A sample with both a proton pre-irradiated and an unirradiated area was exposed to a simulated PWR environment during 24 hours. Irradiation defects and Radiation Induced Segregation at grain boundary and on irradiation defects were characterized and quantified and their effect on the oxidation was evaluated. Irradiation affects the morphology, thickness and chemistry of the oxide layers formed. It enhances the oxidation kinetic and induces the formation of an inner oxide richer in chromium. Defects induced by irradiation act as preferential nucleation sites.

Radionuclide tracing based in situ corrosion and mass transport monitoring of 316L stainless steel in a molten salt closed loop

“…The displacement per atom (dpa) induced by the beam is quite small, about 0.04 dpa, based on the Stopping and Range of Ions in Matter (SRIM) analysis 45 . In 316L SS, a proton irradiation dose of 1-1.5 dpa is considered close to the saturation of the dislocation loops and the radiation induced segregations phenomenon, where effects on post-corrosion rate can be observed 46 . In this study, the damage is about 25 times less than that.…”

Review on synergistic damage effect of irradiation and corrosion on reactor structural alloys

“…For a comprehensive understanding of the composition and structure of the oxide formed on the metal surface, as well as the depth of the inner oxide layer following irradiation, extensive studies have been conducted, which have been summarized in Table 6 [19-21, 76, 82, 83]. Although Deng et al [20] have already reported that a finer oxide grain in the inner oxide film was formed on a 3-dpa proton-irradiated 316 L austenitic stainless steel after exposure to the primary water of the simulated PWR for 500 h, it is generally accepted that irradiation does not alter the crystal structure and the qualitative chemistry of the inner and outer oxides formed on materials, which can be characterized using high-resolution TEM (HRTEM) [19,21,74,77,78,82,84,85]. Similar to the unirradiated sample, the oxide layer maintains its characteristic double-layer structure when stainless steel is irradiated.…”

“…Both layers have been characterized as spinel structures. In addition, Ni enrichment at the oxide/ matrix interface has been observed [19,82]. However, based on the available study data [19-21, 74, 76, 82, 85-89], it has been observed that irradiation affects the quantitative chemistry, morphology, and thickness of the oxide layers formed on the alloys.…”

“…However, owing to the diversity and complexity of its influencing factors, it is difficult to unravel its intricacies. To date, many experimental and theoretical studies have been conducted on the service behavior of structural materials subjected to irradiation and corrosive environments [19][20][21][22][23][24] in PWRs. The rupturing of an oxide film under stress is the first step in stress corrosion cracking (SCC).…”

Investigating radiation-induced segregation on intragranular defects in a 316L(N)

“…Many authors observed RIS on different types of sinks, i.e. grain boundaries [4,[7][8][9][10][11], dislocation loops [10][11][12][13][14] and lines [11,15] and cavities [8,13,14]. (S)TEM and APT are extensively used to study microstructural features induced by radiation damage because of their complementarity: accurate crystallography information for TEM and accurate composition measurements for APT.…”