In situ conductivity study of the corrosion layers on lead-tin alloys in sulfuric acid

Journal Article · Sat Feb 01 04:00:00 EST 1997 · Journal of the Electrochemical Society

DOI:https://doi.org/10.1149/1.1837429· OSTI ID:465087

Mattesco, P; Bui, N; Simon, P ^[1]; Albert, L ^[2]

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1. Ecole Nationale Superieure de Chimie de Toulouse (France)
2. MetalEurop Recherche, Trappes (France)

Cyclic polarization of lead and lead-tin alloys in 4.5 M H{sub 2}SO{sub 4} with and without the ceric-cerous redox couple, from {minus}1,500 to +1,500 mV/Hg-Hg{sub 2}SO{sub 4} sat. K{sub 2}SO{sub 4}, showed that during polarization in the anodic direction up to {minus}200 mV, the PbSO{sub 4} film was electronically conducting. When PbO was formed under the sulfate layer, the duplex passive film was nonconducting and an anodic passive current was observed up to the formation potential of PbO{sub 2}. During reverse polarization from +1,500 mV, after PbO{sub 2} reduction, the passive film on lead was shown to be nonconducting. When the tin content in the alloy was higher than 1.0 weight percent (w/o), the conductivity of this passive film was largely increased. It reduces the thickness of the PbO layer. After alloy oxidation at +1,500 mV, chronopotentiometric curves revealed the presence of PbO{sub 2}, PbO{sub x}, and PbO. PbO{sub x} can be gradually reduced at decreasing potentials below +800 mV because of its nonstoichiometric nature. Two steps were demonstrated in the reduction of PbO{sub 2}. Alloying tin at more than 1.5 w/o appears to favor the growth of PbO{sub x} and PbO{sub 2}.

• Sponsoring Organization: European Economic Community, Brussels (Belgium)
• OSTI ID: 465087
• Journal Information: Journal of the Electrochemical Society, Journal Name: Journal of the Electrochemical Society Journal Issue: 2 Vol. 144; ISSN 0013-4651; ISSN JESOAN
• Country of Publication: United States
• Language: English

Related Subjects

25 ENERGY STORAGE
36 MATERIALS SCIENCE
CORROSION
ELECTRIC CONDUCTIVITY
LEAD ALLOYS
LEAD OXIDES
LEAD SULFATES
LEAD-ACID BATTERIES
METALLURGICAL EFFECTS
PASSIVATION
PROTECTIVE COATINGS
SULFURIC ACID
TIN
TIN ALLOYS