著者

貴堂 高徳 辻川 茂男

出版者

社団法人日本鉄鋼協会

雑誌

鐵と鋼 : 日本鐡鋼協會々誌 (ISSN:00211575)

巻号頁・発行日

vol.75, no.8, pp.1332-1337, 1989-08-01

被引用文献数

1

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Critical conditions to repassivate growing crevice corrosion in terms of electrode potential, E_R, temperature, T_R, and NaCl concentration, C_<NaCl, R>, were determined for metal/metal-crevice of ASTM Grade 12 (G 12 Ti) and Ti-x(=0&acd;2%)Ni-y(=0&acd;0.4%) Mo alloys. G 12 Ti with 0.8%Ni and 0.3% Mo has more noble E_R values than commercially pure Titanium (C.P. Ti) and this tendency is more enhanced in lower concentrations of NaCl solutions. G 12 Ti is predicted to be resistant to crevice corrosion in solutions containing as high as 9% NaCl at 100℃, which is markedly higher than 1% NaCl or less as the highest concentration for C.P. Ti to be resistant at the temperature. E_R value for Ti-xNi-yMo alloy depends almost on Ni content. Sufficiently noble value of E_R is attained for the alloys with Ni contents over 0.2%. The beneficial effect of Ni could be explained from formation of Ti_2Ni which works as Pd does in Ti-0.15 Pd alloy. C_<NaCl, R> depends not only on Ni content but also on Mo content. It decreases with increasing Mo content in the range from 0 to 0.1&acd;0.2%, above which C_<NaCl, R> increases with increasing Mo content. This shows beneficial effect of Mo combined with Ni. Based on the results of Ti-xNi-yMo alloy, characteristics of G 12 Ti are found to be accounted for approximately through its contents of Ni and Mo.