Grease corrosion

The practice of corrosion inhibition requires that the inhibitive species should have easy access to the metal surface. Surfaces should therefore be clean and not contaminated by oil, grease, corrosion products, water hardness scales, etc. Furthermore, care should be taken to avoid the presence of deposited solid particles, e.g. stones, swarf, building materials, etc. This ideal state of affairs is often difficult to achieve but there are many cases where less than adequate consideration has been given to the preparation of systems to receive inhibitive treatment. Acid treatments, notably with 3-5% citric acid, with or without associated detergent washes, are often recommended and adopted for cleaning systems prior to inhibition. However, it is not always appreciated that these treatments will not remove particulate material particularly when, as is often the case, the material is insoluble in acids. 

Use Chemical (reducing agent), lubricating grease (corrosion inhibitor). 

Dextrin is also applied as the component of protective colloids, lubricating greases, corrosion inhibitors, and scale-preventing formulations for water treatment. The stabilization of colloidal AgCl increases the sensitivity of the determination of chloride anions by titration with AgNOj. 

Kemamine S Series. [Witco/Humko] Fatty acid sec. amines grease, corrosion inhibitor industrial use. 

Azelaic acid (AA), 1,9-nonanedioic acid or heptane-1,7-dicarboxylic acid, is used in manifold application areas. AA is offered in the pharmaceutical field for the treatment of acne and rosacea due to its antibacterial effect [1,2]. However, AA is much more widely applied as a monomer for the production of polymers such as alkyd resins, polyamides, and impact-proof polyesters or for the synthesis of plasticizers, lubricants, lithium complex greases, corrosion inhibitors, dielectric fluids, heat-transfer fluids, metal to glass fluxes, emulsion breakers, waxes, tobacco sheet plasticizers, hot-melt coatings and adhesives, water-soluble coating resins, hydraulic fluids, fungicides, insecticides, and so on [3-7]. 

Hazardous Decomp. Prods. Heated to decomp., emits NOx, NHs, POx Storage Hygroscopic keep tightly closed Uses Chemical (reducing agent), lubricating grease (corrosion inhibitor)... 

Uses Surfactant, emulsifier, skin conditioner in cosmetics industrial applies. grease corrosion inhibitor anticaking agent chemical intermediate antioxidant flotation agent surf, lubricant in mfg. of food-contact metallic articles... 

The lower molecular weight PCTFE oils, waxes, and greases are used as inert sealants and lubricants for equipment handling oxygen and other oxidative or corrosive media. Other uses include gyroscope flotation fluids and plasticizers for thermoplastics. 

Although most greases offer some inherent protection against msting, additives, eg, amine salts, sodium sulfonate, cycloparaffin (naphthenate) salts, esters, and nonionic surfactants (qv), are often used to provide added protection against water and salt-spray corrosion. A dispersion of sodium nitrite has been particularly effective in some multipurpose greases. 

Chemical treatments commonly appHed to cormgated paperboard packaging materials include additives that impart various degrees of water resistance, humidity resistance, oil and grease resistance, product abrasion resistance, product corrosion resistance, adhesion release properties, flame-retardant properties, nonskid properties, and static electricity control properties to the finished package (1,2). 

Sulfonic acid salts have found widespread use in the area of corrosion inhibition. Lubrizol Corporation produces a wide variety of sulfonic acids, particularly in the form of magnesium salts, for use in lubricant formulations, anticorrosion coatings, greases, and resins (146,147). Petroleum sulfonates are used in epoxy resin elastomers to improve anticorrosion properties of coatings and sealants (qv) (148,149). 

Fretting corrosion (36,37) can lead to high contact resistance of base metal contacts, such as tin plate in electronic connectors. Small cycHcal displacements of the connector halves occur because of external vibration or differential thermal expansion and contraction of the mating contacts. The wear debris that is formed remains in the contact zone. The accumulation of oxide debris in the contact region leads to increased contact resistance. Solutions to this problem are stmctures that do not permit movement of contact surfaces with respect to one another, the use of gold as a contact finish, and the appHcation of thick coatings of contact lubricants and greases, which reduce the rate of wear and restrict access of air to the contact surfaces. 

In addition to films that originate at least in part in the corroding metal, there are others that originate in the corrosive solution. These include various salts, such as carbonates and sulfates, which may be precipitated from heated solutions, and insoluble compounds, such as beer stone, which form on metal surfaces in contac t with certain specific products. In addition, there are films of oil and grease that may protect a material from direct contact with corrosive substances. Such oil films may be apphed intentionally or may occur naturally, as in the case of metals submerged in sewage or equipment used for the processing of oily substances. 

Recommendations were made to begin treatment with corrosion inhibitors and to make system operation changes to reduce grease and oil fouling. Other water chemistry recommendations involved reducing the amount of aggressive anion in solution and pursuing biocidal treatment. 

Almost all cooling water system deposits are waterborne. It would be impossible to list each deposit specifically, but general categorization is possible. Deposits are precipitates, transported particulate, biological materials, and a variety of contaminants such as grease, oil, process chemicals, and silt. Associated corrosion is fundamentally related to whether deposits are innately aggressive or simply serve as an occluding medium beneath which concentration cells develop. An American... 

Petroleum greases and oils can be excellent corrosion inhibitors on a variety of alloys. The hydrophobic layer produced by oil or grease can prevent water from contacting surfaces and can, therefore, almost eliminate corrosion. Unfortunately, the addition of oil and grease cannot be recommended as a corrosion-reduction measure in cooling water systems for three basic reasons. 

First, greases and oils serve as binders that accumulate and hold large amounts of potentially corrosive substances. Second, greases and... 

The cranking screw and the guide rails on which the trolley slides must also be coated with ordinary grease to provide a smoother operation and to prevent corrosion. 

Some of the more obvious sources of contamination of solvents arise from storage in metal drums and plastic containers, and from contact with grease and screw caps. Many solvents contain water. Others have traces of acidic materials such as hydrochloric acid in chloroform. In both cases this leads to corrosion of the drum and contamination of the solvent by traces of metal ions, especially Fe. Grease, for example on stopcocks of separating funnels and other apparatus, e.g. greased ground joints, is also likely to contaminate solvents during extractions and chemical manipulation. 

Corrosive Liquid Chemical pH Constituent analysis Oil and grease content Total suspended solids Total dissolved solids... 

Chemical Reactivity - Reactivity with Water Reacts slowly to form flammable hydrogen gas, which can accumulate in closed area Reactivity with Common Materials Corrosive to natural rubber, some synthetic rubbers, some greases and some lubricants Stability During Transport Stable Neutralizing Agents for Acids and Caustics Flush with 3% aqueous ammonia solution, then with water. Methyl alcohol may also be used Polymerization Not pertinent Inhibitor of Polymerization Not pertinent. 

MEA systems foam rather easily resulting in excessive amine can y over from the absorber. Foaming can be caused by a number of foreign materials such as condensed hydrocarbons, degradation products, solids such as carbon or iron sulfide, excess corrosion inhibitor, valve grease, etc. Solids can be removed with cartridge filters. Hydrocarbon liquids aie usually removed in the flash tank. Degradation products are removed in a reclaimer as previously described. 

Because a film of grease remains where it is applied for much longer than a film of oil, it provides better protection to bearing and other surfaces that are exposed to shock loads or sudden changes of direction. A film of grease also helps to prevent the corrosion of machine parts that are idle for lengthy periods. 

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