Effect of Benzotriazole on the Localized Corrosion of Copper Covered with Carbonaceous Residue

• Published in: Materials Vol. 14; no. 11; p. 2722
• Main Authors: Lee, Yun-Ho, Hong, Min-Sung, Ko, Sang-Jin, Kim, Jung-Gu
• Format: Journal Article
• Language: English
• Published: Basel MDPI AG 21-05-2021; MDPI
• Subjects: Annealing; Benzotriazole; BTA inhibitor; carbonaceous residue; Concentration cell corrosion; Copper; copper corrosion; Corrosion cell; Corrosion effects; Corrosion inhibitors; Corrosion mechanisms; Corrosion resistance; Corrosion tests; Crevice corrosion; Drinking water; Efficiency; Electrodes; Energy; Experiments; Galvanic corrosion; inhibition; Localized corrosion; Manufacturing; Photoelectrons; Pipes; Pitting (corrosion); Residues; Scanning electron microscopy; X ray photoelectron spectroscopy; United Kingdom > UK; Japan
• ISSN: 1996-1944; 1996-1944
• DOI: 10.3390/ma14112722

Carbonaceous residues on copper pipes during the manufacturing process are known to be one of the main causes of pitting corrosion on copper pipes. This study examined the corrosion-inhibiting effect of benzotriazole (BTA) on C12200 copper pipes with carbonaceous film in synthetic tap water. In the absence of BTA, localized corrosion mechanisms due to galvanic corrosion, crevice corrosion, and oxygen-concentration cell were proposed in the boundary part of the carbonaceous film on the copper through X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM) with energy dispersive spectrometer (EDS) analyses. Electrochemical tests showed that BTA inhibits corrosion by forming Cu−BTA complexes on all over the copper surface where carbonaceous film is present. BTA mitigates galvanic corrosion and crevice corrosion at the boundary of the carbonaceous film and suppresses the formation of oxygen-concentration cells through the formation of a Cu−BTA complex.