تخصصی--20 صفحه--محصول 1980--
لینک دانلود رایگان-->>
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SUMMARY
The inhibition of atmospheric corrosion of both ferrous and nonferrous metals
demands the application of chemical compounds which posses high passivating properties,
strong tendencies toward surface adsorption, and the ability to form a comparatively
strong and stable bond with metal surface. The delicate and yet complex nature of
atmospheric corrosion processes occurring under thin films of electrolyte preordains the
transport mechanism of corrosion inhibitor which- in order to become effective, must
diffuse through the electrolyte film and cover the substantial portion of the surface. The
precise parameters of the corrosion inhibiting mechanism are still unknown. It is believed
that certain physical and chemical properties of the benevolent molecules are critically
important, e.g., vapor pressure saturation levels, molecular structural characteristics,
availability of reactive groups for surface physical or chemical binding, the polarity, the
contamination, the resultant conductivity of the electrolyte, etc. There is a considerable
controversy over the importance of, and the relationship between the saturated vapor
pressure and its influence on the effectiveness of the specific VCI compound. Various
investigations have either (1) emphasized the significance of minimum acceptable values of
vapor pressure to achieve vaporization or (2) stressed the importance of electrochemical
factors in altering the kinetics of partial corrosion processes. The many critical
requirements made on an inhibitor of atmospheric corrosion have severely limited the
number of compounds acceptable to solve the practical corrosion problems existing in the
industry
FUNDAMENTAL PRINCIPLES OF CORROSION PROTECTION WITH VAPOR PHASE INHIBITORS