Effect of lead content on the dezincification behaviour of leaded brass in neutral and acidified 3.5% NaCl solution

Kumar, Satendra; Narayanan, T.S.N. Sankara; Manimaran, A.; Kumar, M Suresh

doi:10.1016/j.matchemphys.2007.05.030

Cited by 28 publications

(15 citation statements)

References 26 publications

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“…The results were consistent with those of Heidersbach and Verink 23 who proposed that preferential dissolution of Zn occurred at low potentials, while for higher potentials, both copper and Zn dissolved with or without copper re-deposition depending on the potential value. They were also in good agreement with other authors 20,[24][25] who showed that the precipitation of lead based compounds on the surface of the brass, for potentials higher than the corrosion potential, decreases the extent of corrosion attack. Results from a previous study 16 brought a new insight into the chemical composition of the surface layer depending on the pH and the applied potential.…”

supporting

confidence: 92%

Dissolution Kinetics of α,β^′-Brass in Basic NaNO₃Solutions

Berne

Andrieu

Reby

et al. 2015

J. Electrochem. Soc.

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Corrosion tests at a constant anodic potential, referred to as dissolution tests, were performed to determine the dissolution kinetics of an α,β′-brass CuZn40Pb2 (CW617N) in a basic nitrate solution with and without mechanical loading. The corrosion behavior of the α,β′-brass was characterized by a two-step mechanism, with an initiation step for which the simultaneous dissolution of all the alloying elements of the β′ phase occurred only and a propagation step including at first, the afore-mentioned simultaneous dissolution process before a critical time tc and then, both simultaneous dissolution and dezincification of the β′ phase after tc. The pH and Cu concentration of the electrolyte near the brass surface were determined to be two of the major factors influencing the occurrence of the dezincification process. The dezincification of the β′ phase extended in depth by a percolation dissolution mechanism. Mechanical loading during the dissolution tests was observed to largely influence the dezincification process. It was assumed to open or close the pores present in the dezincified β′ phase, which promoted or slowed down the dezincification mechanism depending on the sign of the stress.

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supporting

confidence: 92%

Dissolution Kinetics of α,β^′-Brass in Basic NaNO₃Solutions

Berne

Andrieu

Reby

et al. 2015

J. Electrochem. Soc.

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“…It is of interest to recall at this stage that lead particles were mainly present inside the β phase and, for pH 11, only local corrosion phenomena were observed on the β phase after the passivity breakdown. Therefore, Pb particles were still present on the surface exposed to the electrolyte after the passivity breakdown and, under anodic polarization, Pb oxides were incorporated into the passive layer as suggested by Kumar et al 18 The Cu 2 O/PbO layer constituted an efficient protection against corrosion even if local corrosion phenomena were observed on the β phase. In contrast, at pH 12, on the pseudo-passivity plateau, the surface layer was mainly constituted of Cu(OH) 2 and CuO.…”

Section: Influence Of the Applied Potential On The Dissolution Mechanmentioning

confidence: 98%

The Electrochemical Behavior of α,β^′-Brass in Basic NaNO₃Solutions

Berne¹,

Andrieu²,

Reby³

et al. 2015

J. Electrochem. Soc.

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The electrochemical behavior of an α,β -brass CuZn40Pb2 (CW617N) was studied in basic nitrate solutions with various basic pHs and nitrate ion concentrations. In all the chosen experimental conditions, corrosion at the open circuit potential proceeded by the galvanic coupling of the α and β phases, leading to a surface dezincification of the β phase. The study showed that the extent of the dezincification was affected by the presence of lead in the alloy but the pH was the major parameter. During polarization tests, a pseudo-passive or a passive stage followed by a breakdown was observed: corrosion phenomena mainly involved copper and zinc dissolution from the β phase. At pH 11, a Cu 2 O/PbO layer was efficient in achieving passivity of the brass. At pH 12, a Cu(OH) 2 -rich surface layer was formed: it was not protective enough, and complete dissolution of the β phase was observed leading to the removal of lead particles.

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“…In all of these components, the brasses are usually shaped into semi-finished product by means of extrusion, rolling, stamping, cold forming or machining. To increase the machinability of brass, 1% -3% lead is usually added to enhance chip fracturing, reduce cutting force, increase the machining rate and ease of productivity, reduce tool wear rate and improve surface finish [3] [4]. The machinability of brasses is improved by addition of lead, sulfur, tellurium and zinc [5] while it deteriorates when tin and iron are added [6] [7].…”

Section: Introductionmentioning

confidence: 99%

Mechanical and Microstructural Evaluation of Plastically Deformed Brass

Bodude

Momohjimoh

Nnaji

2015

MSA

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The mechanical properties as well as microstructure of Cu-30.6 wt% Zn alloys containing 0.01 wt% lead has been investigated. The brass alloy was cast and then cold rolled at various percentage reductions: 20%, 25%, 30%, 35% and 40% followed by stress relieving annealed at 450˚C. Hardness, ultimate tensile strength (UTS) and impact toughness values were evaluated at every stage of reduction. It was discovered that the strength, hardness and impact energy all increased with increased percentage reduction. Finally, the optical microscope of the samples was done and the result achieved correlated with the mechanical properties.

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Effect of lead content on the dezincification behaviour of leaded brass in neutral and acidified 3.5% NaCl solution

Cited by 28 publications

References 26 publications

Dissolution Kinetics of α,β^′-Brass in Basic NaNO₃Solutions

Dissolution Kinetics of α,β^′-Brass in Basic NaNO₃Solutions

The Electrochemical Behavior of α,β^′-Brass in Basic NaNO₃Solutions

Mechanical and Microstructural Evaluation of Plastically Deformed Brass

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Effect of lead content on the dezincification behaviour of leaded brass in neutral and acidified 3.5% NaCl solution

Cited by 28 publications

References 26 publications

Dissolution Kinetics of α,β′-Brass in Basic NaNO3Solutions

Dissolution Kinetics of α,β′-Brass in Basic NaNO3Solutions

The Electrochemical Behavior of α,β′-Brass in Basic NaNO3Solutions

Mechanical and Microstructural Evaluation of Plastically Deformed Brass

Contact Info

Product

Resources

About

Dissolution Kinetics of α,β^′-Brass in Basic NaNO₃Solutions

Dissolution Kinetics of α,β^′-Brass in Basic NaNO₃Solutions

The Electrochemical Behavior of α,β^′-Brass in Basic NaNO₃Solutions