Effect of halogenation on yellow metal corrosion: Inhibition by triazoles

Journal Article · Wed Jun 01 04:00:00 EDT 1994 · Corrosion (Houston); (United States)

DOI:https://doi.org/10.5006/1.3293520· OSTI ID:7268677

Lu, F; Rao, N M; Yang, B; Hoots, J E; Budrys, R S ^[1]

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1. Nalco Chemical Co., Naperville, IL (United States)

Tolyltriazole (TT) is fed continuously into recirculating cooling water systems to inhibit corrosion of copper (Cu)-alloy heat exchangers. The adsorption isotherm and the corrosion rate profile for TT and butylbenzotriazole (BBT) were presented as functions of immersion time in triazole solution. Formation of a triazole film on a yellow metal surface was shown to play a major role in corrosion inhibition. In the absence of triazole in bulk solution, halogenation was detrimental to TT and BBT surface films. The disruption mechanism was attributable to chemical decomposition of the adsorbed triazole by halogen. However, adding TT (> 0.2 mg/l) to the halogen-based biocide solution improved stability of the protective TT film significantly. The improvement in stability was evident from the nearly unchanged surface coverage and lower corrosion rate. Based on this result, an enhanced TT-intermittent-feed method was developed. The metal surface was passivated initially with TT. Addition of halogen-based biocide was accompanied by a concurrent addition of TT (0.5 mg/l to 2 mg/l). Results demonstrated that the enhanced TT-intermittent-feed method performed better than the initial slug feeding of TT and BBT in inhibiting yellow metal corrosion.

• OSTI ID: 7268677
• Journal Information: Corrosion (Houston); (United States), Journal Name: Corrosion (Houston); (United States) Vol. 50:6; ISSN 0010-9312; ISSN CORRAK
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360105* -- Metals & Alloys-- Corrosion & Erosion
ADSORPTION ISOTHERMS
ALLOYS
AZOLES
BIOLOGICAL FOULING
COPPER ALLOYS
COPPER BASE ALLOYS
CORROSION INHIBITORS
CORROSION PROTECTION
FOULING
HEAT EXCHANGERS
HETEROCYCLIC COMPOUNDS
ISOTHERMS
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
PERFORMANCE
TRIAZOLES