Organic inhibitors film-forming

Alkalizing and film-forming inhibitors are used to prevent corrosion in water containing Oj or salt. These include NajCOj, NaOH, Na3P04, Na2Si03, NaNOj and Na2Cr04. The number of organic compounds that effectively inhibit metal... 

The oil enmeshes in the tail, as shown in Figure 4-480, and provides a mechanical barrier to attack of the aqueous corrodents on the base metal. The oily film also increases the resistance to corrosion current flow and, thus, stifles the rate of corrosion. An advantage of using organic film-forming inhibitors... 

M. V. Enzien, D. H. Pope, M. M. Wu, and J. Frank. Nonbiocidal control of microbiologically influenced corrosion using organic film-forming inhibitors. In Proceedings Volume. 51st Annu NACE Int Corrosion Conf (Corrosion 96) (Denver, CO, 3/24—3/29), 1996. 

The inhibitors used in acid systems consist of organic amines which form an inhibitor film due to Fe-N interactions. Other inhibitors used consist of acetylenic alcohols such as propargyl alcohol. 

The inhibitors used in acid systems are organic amines, which form an inhibitor film because of Fe-N inferacfions. Other inhibitors such as acetylenic alcohols (propargyl alcohol) may be used. 

Inhibitors may be classified as shown in Fig. 6.1. There are two major classes inorganic and organic. The anodic type of inorganic inhibitors includes chromates, nitrites, molybdates and phosphates, and the cathodic type includes zinc and polyphosphate inhibitors. The film forming class is the major class of organic inhibitor as it includes amines, amine salts and imidazolines - sodium benzoate mercaptans, esters, amines and ammonia derivatives. 

The typical increase in corrosion inhibition with inhibitor concentration, suggests that inhibition is the result of adsorption of inhibitor on the metal surface. The film formed by adsorption of soluble organic inhibitors is only a few molecules thick and is invisible. 

Therefore, the stronger the adsorption bond, the lower the concentration of inhibitor in solution required to achieve a given coverage of the surface. Soluble organic inhibitors form a protective layer only a few molecules thick, but if an insoluble organic inhibitor is added by dispersion as fine droplets, the film may continue to build to a thickness of several thousandths of an inch. 

Another approach is to reduce the amount of ammonia added for neutrahzation and operate at a lower pH, and instead use organic film-forming inhibitors to control corrosion. The frequency of this approach has increased because of the development of inhibitors active over a wider pH range than... 

Corrosion inhibitors are often emulsions that are able to form an organic film on the parts to be protected. 

Corrosion inhibitor - corrosion inhibitors are chemicals which are added to the electrolyte or a gas phase (gas phase inhibitors) which slow down the - kinetics of the corrosion process. Both partial reactions of the corrosion process may be inhibited, the anodic metal dissolution and/or the cathodic reduction of a redox-system [i]. In many cases organic chemicals or compounds after their reaction in solution are adsorbed at the metal surface and block the reactive centers. They may also form layers with metal cations, thus growing a protective film at the surface like anodic oxide films in case of passivity. Benzo-triazole is an example for the inhibition of copper cor-... 

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