ABSTRACT

Development of countermeasure for corrosion and hydrogen embrittlement of Ni-Ti superelastic alloy in an acidulated phosphate fluoride (APF) solution has been attempted by adding NaHCO₃ and H₂O₂ to the solution. Upon addition of only 0.001 M NaHCO₃ to a 0.2% APF solution, almost no changes in corrosion current density and corrosion potential are observed. With an increasing NaHCO₃ concentration up to 0.01 M, the corrosion current density substantially decreases and the corrosion potential slightly shifts in the noble direction. The corrosion loss significantly decreases and hydrogen absorption is slightly inhibited. Upon the combined addition of 0.01 M NaHCO₃ and 0.001 M H₂O₂, the corrosion current density is lowest and the corrosion potential shifts in the noble direction. The corrosion and hydrogen absorption are substantially inhibited. The present study clearly indicates that the combined addition is exceptionally effective as a simultaneous countermeasure for corrosion and hydrogen embrittlement of the alloy.

摘要

已尝试通过向溶液中添加 NaHCO ₃和 H ₂ O ₂来开发针对酸化磷酸盐氟化物 (APF) 溶液中 Ni-Ti 超弹性合金的腐蚀和氢脆的对策。在仅将 0.001 M NaHCO _{3 添加}到 0.2% APF 溶液中时，几乎没有观察到腐蚀电流密度和腐蚀电位的变化。随着 NaHCO ₃浓度增加到 0.01 M，腐蚀电流密度显着降低，腐蚀电位略微向贵方向移动。腐蚀损失显着降低，吸氢受到轻微抑制。在组合添加 0.01 M NaHCO ₃和 0.001 MH 后₂ O ₂，腐蚀电流密度最低，腐蚀电位向贵方向移动。腐蚀和氢吸收基本上被抑制。本研究清楚地表明，联合添加作为同时对抗合金腐蚀和氢脆的措施非常有效。