低温FACによる減肉速度に及ぼす鋼材Cr含有量と溶存酸素濃度の組合せ影響評価

英字タイトル:
Combined Effect of Cr content and Dissolved Oxygen Concentration on Wall Thinning Rate by Low Temperature FAC
著者:
岸拓海阿部博志渡邉豊（東北大）藤原和俊（電中研）
発刊日: 2021年7月 6日
公開日: 2021年9月30日

カテゴリ: 第17回

キーワードタグ:
Carbon SteelCr ContentDissolved OxygenFlow Accelerated Corrosion

概要

Flow Acceleration Corrosion (FAC) is one of the mechanisms of pipe wall thinning in power plants. The wall thinning caused by FAC is usually found between 90 ℃ and 230 ℃ with a peak at about 150 ℃. However, FAC has been reported at temperatures below this range. This study evaluated the effect of DO and Cr content on wall thinning rate at 50 ℃. Raman spectroscopy was performed to identify the constituent species of the oxide film. FAC rate was seen to decrease by increasing Cr content. In terms of DO, wall thinning was suppressed above Cr:0.043wt% in the 10 ppbDO. Regardless of the Cr content, wall thinning was suppressed in all specimens in the 20 ppbDO. These specimens with suppressed wall thinning showed Raman peaks suggesting the formation of Fe2O3.