圧力技術
Online ISSN : 1347-9598
Print ISSN : 0387-0154
ISSN-L : 0387-0154
論文
CCTでの水素存在状態と脆化評価方法
土田 豊千田 徹志大村 朋彦平上 大輔
著者情報
ジャーナル フリー

2021 年 59 巻 2 号 p. 61-69

詳細
抄録

The amount of trapped hydrogen was determined with the aid of Gaussian distribution function, to study the state of hydrogen. In CCT (cyclic corrosion test), hydrogen absorption is cyclically interrupted, and this causes the delay of hydrogen saturation. The V alloyed steel, which contains strong hydrogen trap sites, desorbs hydrogen limitedly: It attains the equilibrium state to the environment in rather short-term exposure to CCT environment. Com-bining the amount of the strongly trapped hydrogen with Fermi-Dirac statis-tics, the hydrogen occupation at lattice site (the occupancy, in short) was successfully determined as 4×10-7. This value is not affected by the kind of steel or the amount of pre-straining; it only depends to the environment. In the case of immersion in ammonium thiocyanate aqueous solution, the occu-pancy has a power law relationship with the concentration of the solution and this allows to determine the concentration of ammonium thiocyanate, which is equivalent to CCT exposure, as 0.5%. The experimental methods with this hydrogen charging solution were additionally explored for evaluat-ing the hydrogen embrittlement. (170 words)

著者関連情報
© 2021 一般社団法人 日本高圧力技術協会
前の記事 次の記事
feedback
Top