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Vol.43, No.3, 224 ~ 231, 2005
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| Title |
| A Study of Additional Chromium Effects on the Electrochemical Characteristics of Cu-6Ni-4Sn Alloys |
| 박창규 Chang Gyu Park , 김정구 Jung Gu Kim , 안승호 Seung Ho Ahn , 한승전 S. Z. Han |
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| Abstract |
| Corrosion characteristics of Cu-6%Ni-4%Sn-x%Cr alloys in a acid-chloride solution (0.1M H₂SO₄+ 0.0056M NaCl) at pH = 6, were studied as a function of chromium addition. Three kinds of Cu-6%Ni-4%Sn-x%Cr alloys were prepared by melting, and casting, followed by thermomechanical treatments. The corrosion behavior of Cu-6%Ni-4%Sn-x%Cr alloys was investigated by electrochemical corrosion tests (potentiodynamic polarization test, electrochemical impedance spectroscopy) and surface analyses (optical microscopy, electron probe micro analysis, scanning electron microscopy). Cr additions were found to prevent the localized corrosion behavior. This is the reason that the small addition of Cr promoted the decomposition behaviors of the supersaturated solid solution a in Cu-6%Ni-4%Sn alloy, i.e., the number of like-Sn-rich carbide impurities (LCI), which increased the galvanic effect between the matrix and the LCI, decreased with increasing the Cr addition. (Received September 8, 2004) |
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| Key Words |
| Cu-Ni-Sn alloy, Aacid-chloride solution, Localized corrosion, Sn-rich, Galvanic effect |
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