Effects of the hydrogen absorption conditions on the hydrogen embrittlement behavior of Ni-Ti superelastic alloy

Ken'ichi Yokoyama, Akira Nagaoka, Jun'ichi Sakai

    Research output: Contribution to journalArticle

    12 Citations (Scopus)

    Abstract

    The present study has investigated whether the hydrogen embrittlement behavior of Ni-Ti superelastic alloy can be changed by modifying the hydrogen absorption conditions. Upon immersion in H 2SO 4 or H 3PO 4 solution, the stress plateau due to the stress-induced martensite transformation becomes unclear and forms a gentle slope. In addition, the superelastic strain decreases with increasing immersion time. The peripheral part of the fracture surface of the immersed specimens is flat as usual, whereas the center part of the fracture surface is rough compared with that under other hydrogen absorption conditions reported previously. For the specimens immersed in H 3PO 4 solution, hydrogen thermal desorption tends to be observed at higher temperatures compared with the specimens immersed in H 2SO 4 solution. Moreover, for a longer immersion time, a second peak of hydrogen desorption is observed at a high temperature, indicating that the hydrogen states change with the hydrogen absorption conditions. The results of this study suggest that changing the hydrogen embrittlement behavior by modifying the hydrogen absorption conditions may enable the determination of the embrittlement mechanism of the alloy. ent.

    Original languageEnglish
    Pages (from-to)255-262
    Number of pages8
    JournalISIJ International
    Volume52
    Issue number2
    DOIs
    Publication statusPublished - 2012

    Keywords

    • Corrosion
    • Hydrogen absorption
    • Hydrogen embrittlem
    • Martensite
    • Nitinol
    • Shape memory alloy

    ASJC Scopus subject areas

    • Mechanical Engineering
    • Mechanics of Materials
    • Materials Chemistry
    • Metals and Alloys

    Fingerprint Dive into the research topics of 'Effects of the hydrogen absorption conditions on the hydrogen embrittlement behavior of Ni-Ti superelastic alloy'. Together they form a unique fingerprint.

  • Cite this