検索対象:     
報告書番号:
※ 半角英数字
 年 ~ 
 年

Correlation between intergranular corrosion and impurities of extra high purity austenitic stainless steels

超高純度オーステナイトステンレス鋼の不純物と粒界腐食の相関性

井岡 郁夫; 鈴木 潤; 本岡 隆文; 木内 清; 中山 準平*

Ioka, Ikuo; Suzuki, Jun; Motooka, Takafumi; Kiuchi, Kiyoshi; Nakayama, Jumpei*

再処理施設の沸騰硝酸環境において、粒界腐食はオーステナイト・ステンレス鋼の重大な劣化事象である。粒界腐食の主要因は、結晶粒界への不純物元素の偏析が原因と考えられている。新たな複合溶製技術により、全有害不純物を100ppm以下に抑えた超高純度(EHP:Extra High Purity)オーステナイト・ステンレス鋼を開発した。C, P, S, B等の不純物元素を添加したEHP合金を作製して、粒界腐食と不純物元素量の相関性を調べた。得られた結果を重回帰分析し、粒界腐食に及ぼす不純物元素の影響度を示した。その結果、B, P, Si, C, Sの順に粒界腐食に大きな影響を与え、Mnの影響は少なかった。

An intergranular corrosion is an important degradation mechanism of austenitic stainless steels for use in a nuclear fuel reprocessing plant. The intergranular corrosion is caused by the segregation of impurities to grain boundaries. An extra high purity austenitic stainless steel (EHP) was developed with conducting the new multiple refined melting to suppress the impurities less than 100ppm. The intergranular corrosion behavior of EHP alloys added various impurities was examined in boiling nitric acid solution with highly oxidizing ions. A multi regression analysis was performed using the obtained data. The degree of influence of the impurities on intergranular corrosion was shown from the analysis. The influence on corrosion rate became small in order of B, P, Si, C, S and Mn. There is little effect of Mn on corrosion rate of EHP-SSs in case of 10000appm or less.

Access

:

- Accesses

InCites™

:

Altmetrics

:

[CLARIVATE ANALYTICS], [WEB OF SCIENCE], [HIGHLY CITED PAPER & CUP LOGO] and [HOT PAPER & FIRE LOGO] are trademarks of Clarivate Analytics, and/or its affiliated company or companies, and used herein by permission and/or license.