DSpace university logo mark
Japanese | English 

NAOSITE : Nagasaki University's Academic Output SITE > 060 工学部・工学研究科 > 060 学術雑誌論文 >


ファイル 記述 サイズフォーマット
JSMS30_133.pdf947.25 kBAdobe PDF本文ファイル

タイトル: 高力ボルト綱中の水素拡散に及ぼす焼入れ焼もどし組織
その他のタイトル: Effect of Quenched and Tempered Microstructures on Diffusion of Hydrogen in High Tensile Strength Bolt Steel
著者: 坂本, 芳一 / 高尾, 慶蔵 / 大渕, 一見
著者(別表記) : Sakamoto, Yoshiichi / Takao, Keizo / Obuchi, Hitomi
発行日: 1981年 2月15日
出版者: 日本材料学会 / The Society of Materials Science, Japan
引用: 材料, 30(329), pp.133-138; 1981
抄録: The effects of quenched and tempered microstructures on the diffusion coefficient and solubility of hydrogen in high tensile strength bolt steel have been investigated by means of the electrochemical permeation technique. The results obtained are as follows : (1) The diffusion coefficient was minimum when the steel had the as-quenched martensitic structure or the low temperature tempered martensite, and it increased with increasing tempering temperature. The mixed structure of ferrite and lamellar pearlite obtained by furnace cooling from a temperature above Ac_3 gave a higher diffusion coefficient than the tempered spheroidal pearlite. On the other hand, the solubility of hydrogen showed a behavior opposite to the diffusion coefficient. (2) The low diffusion coefficient and high solubility are attributed predominantly to hydrogen trapping at the lattice imperfections, such as dislocations and faults etc., which were introduced by martensitic transformation during quenching. (3) With regard to the effect of cathodic current density, i. e., the hydrogen concentration directly below the surface on hydrogen diffusion in tempered steel, the diffusion coefficient hardly depended upon the hydrogen concentration but the solubility of hydrogen increased up to a certain value with increasing cathodic current density. On the other hand, the hydrogen permeation current efficiency decreased with increasing cathodic current density. (4) The activation energies for hydrogen diffusion in the tempered martensite, tempered fine and/or spheroidal pearlites in the temperature range of 6 to 61℃, were almost constant (about 8. 1 kcal/mol) but the pre-exponential factor increased with tempering temperature. The heats of solution of hydrogen in the tempered martensite and tempered pearlites were almost the same (about - 10. 3 kcal/mol) , indicating the exothermic reaction. However, the pre-exponential factor decreased with increaing tempering temperature.
キーワード: 高力ボルト綱 / 水素拡散 / 焼入れ焼もどし組織
URI: http://hdl.handle.net/10069/24678
ISSN: 05145163
権利: Copyright© 日本材料学会
資料タイプ: Journal Article
原稿種類: publisher
出現コレクション:060 学術雑誌論文

引用URI : http://hdl.handle.net/10069/24678



Valid XHTML 1.0! Copyright © 2006-2015 長崎大学附属図書館 - お問い合わせ Powerd by DSpace