Author(s)

Yuma Kano¹, Itaru Ikeda², Takashi Iyasu³, Yuna Yamaguchi¹, Yutaka Yamada^1,4, Osamu Sakurada^1*

¹Department of Chemistry and Biomolecular Science, Faculty of Engineering, Gifu University, Gifu, Japan.
²Dai-Dan Co., Ltd., Saitama, Japan.
³Kurita Water Industries Ltd., Tokyo, Japan.
⁴Daiwa Techno Co., Ltd., Gifu, Japan.

It was well known that residual carbon on the inner surface of copper tubes was a cause of pitting corrosion, and copper tube surfaces with different residual carbon amount were different corrosion forms. In this study, the relation between corrosion form and elution of copper in immersion tests by accelerated corrosion test solutions was examined. Generally, pitting corrosion that occurs in actual machines was reported to observe chloride ion at the bottom of the pitting corrosion of copper tubes. Energy dispersive X-ray (EDX) mapping analysis indicated that chlorine was concentrated in the upper layer of the samples where copper was not detected under conditions of low residual carbon amount, while chlorine was concentrated under part of the micromounds (including the bottom of the pits) under conditions of high residual carbon amount. It was also suggested that the amount of copper eluted was related to the amount of residual carbon.

Carbon Film, Residual Carbon Amount, Pitting Corrosion, Corrosive Anion, The Pitting Corrosion Resistance Test

Kano, Y. , Ikeda, I. , Iyasu, T. , Yamaguchi, Y. , Yamada, Y. and Sakurada, O. (2022) Relationship between Corrosion Form and Elution Behavior of Copper Tubes Surfaces with Different Residual Carbon Amounts. Materials Sciences and Applications, 13, 595-602. doi: 10.4236/msa.2022.1312037.