Inhibition of hydrogen embrittlement of Ni–Ti superelastic alloy in acid fluoride solution by hydrogen peroxide addition

✍ Scribed by Ken'ichi Yokoyama; Yushin Yazaki; Jun'ichi Sakai

• Publisher: John Wiley and Sons
• Year: 2011
• Tongue: English
• Weight: 867 KB
• Volume: 98A
• Category: Article
• ISSN: 1549-3296
• DOI: 10.1002/jbm.a.33124

✦ Synopsis

Inhibition of the hydrogen embrittlement of Ni-Ti superelastic alloy in an acidulated phosphate fluoride (APF) solution has been attempted by adding various amounts of H 2 O 2 . In a 0.2% APF solution, hydrogen absorption is markedly inhibited by adding H 2 O 2 , although corrosion is slightly enhanced by increasing the amount of added H 2 O 2 . By adding a small amount of H 2 O 2 (0.001M), in the early stage of immersion, hydrogen embrittlement is inhibited and corrosion is only slightly enhanced. Upon adding H 2 O 2 , it appears that the dominant cathodic reactions change from hydrogen evolution to H 2 O 2 reduction reactions, or the surface conditions of the alloy are changed by H 2 O 2 with a high oxidation capability, thereby inhibiting hydrogen absorption. The present study clearly indicates that infinitesimal addition of H 2 O 2 into acid fluoride solutions is effective for the inhibition of the hydrogen embrittlement of the alloy. V