Corrosion Behavior of Different Brass Alloys for Drinking Water Distribution Systems

Metals

Vincenzo Grassi¹  Andrea Balbo¹  Jamal Choucri¹  Cecilia Monticelli¹  Federica Zanotto¹  Ilyass Mansouri²  Mohamed Ebn Touhami³ 

[1] Centro di Studi sulla Corrosione e Metallurgia “A. Daccò”, Dipartimento di Ingegneria, Università di Ferrara, 44122 Ferrara, Italy;International Institute for Water and Sanitation (IEA), National Office of Electricity and the Potable Water, 90000 Rabat, Morocco;Laboratory of Materials Engineering and Environment: Modeling and Application, Faculty of Science, University Ibn Tofail, 14000 Kenitra, Morocco;

关键词: brass;    CuZn36Pb2As;    CuZn21Si3P;    corrosion;    dezincification;    simulated drinking water;    EIS;    SEM-EDS;    long immersion;   

DOI  :  10.3390/met9060649

来源: DOAJ

【 摘 要 】

Some α + β’ brass components of drinking water distribution systems in Morocco underwent early failures and were investigated to assess the nature and extent of the corrosion attacks. They exhibited different corrosion forms, often accompanied by extensive β’ dezincification. In order to offer viable alternatives to these traditional low cost materials, the corrosion behavior of two representative α + β’ brass components was compared to that of brass alloys with nominal compositions CuZn36Pb2As and CuZn21Si3P, marketed as dezincification resistant. CuZn21Si3P is a recently developed eco-friendly brass produced without any arsenic or lead. Electrochemical tests in simulated drinking water showed that after 10 days of immersion CuZn21Si3P exhibited the highest polarization resistance (R_p) values but after longer immersion periods its R_p values became comparable or lower than those of the other alloys. After 150 days, scanning electron microscope coupled to energy dispersive spectroscopy (SEM-EDS) analyses evidenced that the highest dezincification resistance was afforded by CuZn36Pb2As (longitudinal section of extruded bar), exhibiting dealloying and subsequent oxidation of β’ only at a small depth. Limited surface dealloying was also found on CuZn21Si3P, which underwent selective silicon and zinc dissolution and negligible inner oxidation of both α and κ constituent phases, likely due to peculiar galvanic effects.

【 授权许可】

Unknown