Sodium-Water Reaction Characteristics with a Specimen and Target of Ferrite Steel by Water Leakage in Liquid Sodium

다국어 초록 (Multilingual Abstract)

In this study, we observed and analyzed the corrosion phenomena of a specimen and target surface caused by the sodium-water reaction from a water(steam) leakage into sodium in a lipuid sodium atmosphere. The leak site of the specimen was damaged by the wastage phenomena due to corrosion and erosion; a leak hole of the specimen extended from 150 ㎛ to about 200 ㎛. The wastage or damage trace at the target surface was observed to have a diameter of ca. 1000 ㎛. The reopened shape of a specimen was circular and the size of this specimen surface was about 2 ㎜ (diameter) on the sodium side. From the results of EPMA and SEM analysis, the damaged areas are found to be covered with complex compounds, such as(NaOH+Na₂O)？exOy and(NaCrO₂+Na₂CrO₄), mixed with sodium oxides from the sodium-water reaction and Fe or Cr elements from the matrix of the tube material. The temperature of the target surface increased by about 70~90℃ with an exothermic reaction, even when the leakage was small(15mL).