Automobiles inhibitors

Chromates are used to inhibit metal corrosion in recirculating water systems. When methanol was extensively used as an antifree2e, chromates could be successfully used as a corrosion inhibitor for cooling systems in locomotive diesels and automobiles (185). 

Maintenance of a correct inhibitor concentration (level) is particularly important where low-level treatments, e.g. less than 100 p.p.m. are used. Such treatments are, however, usually applied (for economic and effluent reasons) in large capacity systems, and plants of this nature will usually have skilled personnel available for control purposes. In smaller closed systems, e.g. automobile engines, higher concentrations of more than approximately 0-1% are commonly used, but in these applications there is usually a good reserve of inhibitor allowed for in the recommended concentration and routine checking is of less importance. Nevertheless, since these inhibitors are often of the dangerous type, gross depletion may lead to enhanced corrosion. 

Molybdenum disulfide is dispersed in greases and oils for lubrication in volatile carriers it is used to form dry coatings of lubricant. Sodium molybdate is an especially effective corrosion inhibitor on aluminum surfaces and is dissolved in cooling solutions to protect aluminum motor blocks in automobiles. 

Industrial applications of corrosion inhibitors are too numerous to cover in the present context. The inhibitor industry amounts to several billion dollars annually. Applications of inhibitors in petroleum production, oil and gas wells and pipelines, potable water, water cooling towers, acid systems, automobile antifreeze systems, paints, boiler waters,... 

Organo-silica compounds are widely used in a range of industries such as printing, oil production, and mining as lubricants and polishing compounds. They also find domestic use in silicon rubber and aerosol sprays because of their special physical properties, such as viscosity and dielectric constant. These compounds are also recognized as poisons/inhibitors in different catalytic processes, such as in atmospheric scrubbers, automobile exhausts, flammable gas... 

Uhlig s study (7) attempted to measure the costs of corroding structures to both the owner/operator (direct cost) and to others (indirect costs). The total cost of corrosion to owner/operators was estimated by summing the cost estimates for corrosion prevention products and services used in the entire US economy such as coatings, inhibitors, corrosion-resistant metals, and cathodic protection and multiplied these totals by their respective prices. Domestic water heater replacement, automobile internal combustion engine repairs, and replacement of automobile mufflers were selected as examples to estimate the cost to private consumers/users. Adding both the direct and indirect costs, the annual cost of corrosion to the United States was estimated to be 5.5 billion or 2.1% of the 1949 GNR This method was used in Japan and estimated the cost of corrosion at 9.2 billion equivalent to 1-2% of the Japanese GNR. 

Major Applications Explosives, power circuits, 10 energetic materials, hquefied gas fuels,i2 thin fllms,i3 power generation,batteries,lAis fuel cells,steel, gold films, nanopowder, antifreeze fluid for automobiles, ) polymerization inhibitors, tattoo ranoval from skin,22 antiinflammatroy... 

In practice, mixtures of inhibitors are most often used in order to combine several modes of protection. A typical example is the water-cooling circuit of an automobile. It includes a variety of metals and alloys the motor made of aluminum alloy or cast iron, the radiator made of brass or copper and soldered joints containing of lead-tin alloys. The temperature can be below 0° C and then exceed 100° C. An adequate mix of inhibitors must be able to protect the different materials over the entire temperature range under the hydrodynamic conditions to which they are exposed during operation. In addition it should not attack the polymeric materials used in tubes and for seals. 

Sodium molybdate is used as an anodic corrosion inhibitor, effective against pitting corrosion, in a number of applications, such as in automobile anti-freeze products and in water cooling systems. 

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