Corrosion stainless steel minimizes

In unalloyed steel containers formamide discolors slowly during shipment and storage. Both copper and brass are also subject to corrosion, particularly in the presence of water. Lead is less readily attacked. Aluminum and stainless steel are resistant to attack by formamide and should be used for shipping and storage containers where the color of the product is important or when metallic impurities must be minimized. Formamide attacks natural mbber but not neoprene. As a result of the solvent action of formamide, most protective paints and finishes are unsatisfactory when in contact with formamide. Therefore, formamide is best shipped in containers made of stainless steel or in dmms made of, or coated with, polyethylene. Formamide supphed by BASF is packed in Lupolen dmms (230 kg) or Lupolen canisters (60 kg) both in continental Europe and overseas. 

The rate (kinetics) and the completeness (fraction dissolved) of oxide fuel dissolution is an inverse function of fuel bum-up (16—18). This phenomenon becomes a significant concern in the dissolution of high bum-up MO fuels (19). The insoluble soHds are removed from the dissolver solution by either filtration or centrifugation prior to solvent extraction. Both financial considerations and the need for safeguards make accounting for the fissile content of the insoluble soHds an important challenge for the commercial reprocessor. If hydrofluoric acid is required to assist in the dissolution, the excess fluoride ion must be complexed with aluminum nitrate to minimize corrosion to the stainless steel used throughout the facility. Also, uranium fluoride complexes are inextractable and formation of them needs to be prevented. 

Shipment nd Stora.ge, Sulfur monochloride is minimally corrosive to carbon steel and iron when dry. If it is necessary to avoid discoloration caused by iron sulfide formation or chloride stress cracking, 310 stainless steel should be used. Sulfur monochloride is shipped in tank cars, tank tmcks, and steel dmms. When wet, it behaves like hydrochloric acid and attacks steel, cast iron, aluminum, stainless steels, copper and copper alloys, and many nickel-based materials. Alloys of 62 Ni—28 Mo and 54 Ni—15 Cr—16 Mo are useful under these conditions. Under DOT HM-181 sulfur monochloride is classified as a Poison Inhalation Hazard (PIH) Zone B, as well as a Corrosive Material (DOT Hazard Class B). Shipment information is available (140). 

When austenitic stainless-steel tubes are used for corrosion resistance, a close fit between the tube and the tube hole is recommended in order to minimize work hardening and the resulting loss of corrosion resistance. 

Austenitic stainless steels are the most corrosion-resistant of the three groups. These steels contain 16 to 26 percent chromium and 6 to 22 percent nickel. Carbon is kept low (0.08 percent maximum) to minimize carbide precipitation. These alloys can be work-hardened, but heat treatment will not cause hardening. Tensile strength in the annealed condition is about 585 MPa (85,000 Ibf/in"), but workhardening can increase this to 2,000 MPa (300,000 Ibf/in"). Austenitic stainless steels are tough and ducdile. 

Extensive field experience has shown the 50 Cr/50 Ni and 60 Cr/40 Ni alloys to offer the best answer to controlling fuel oil ash corrosion. Type 446 stainless steel also shows acceptable corrosion rates but must be used judiciously due to its low strength at elevated temperatures and weldability. Since components of 50 Cr/50 Ni in contact with vanadium-sodium fuel ash melts still suffer high corrosion rates, they should be designed to minimize the amount of surface area available where ash may accumulate. 

For higher-pressure boilers demineralization is necessary to minimize total dissolved solids in the boiler. This water is normally carried in steel pipework, but if condensate is returned and the condensate has become contaminated (for example, with carbon dioxide or copper ions) more corrosion-resistant materials such as copper are required. Downstream of the boiler, steam pipework is usually steel with steel or stainless steel expansion bellows. 

Pressure vessels and appurtenances should be constructed of stainless steel or other corrosion-resistant materials. Ideally, these steam generators should receive hot demineralized FW to minimize chemical treatment requirements. Alternatively, where a main boiler plant is installed, 100% steam condensate provides a good source of FW. In practice, it is very difficult to accurately control the correct amount of chemical feed. Chemicals are typically restricted to potable grade, deposit control agents such as polyacrylates, and other materials listed under the Code of Federal Regulations, CFR 21 173.310, or National Sanitary Foundation (NSF International) approval system. These boilers may be electrically heated or gas-fired. 

The use of more corrosion-resistant materials, such as certain stainless steels, and an increased pitch in condensate lines to minimize temperature drop and limit the pickup of both carbon dioxide and oxygen. 

The increased use of factory-applied epoxy coatings, stainless steel, GRP, and other plastics is to be encouraged, as they are all aids to minimizing tower corrosion from the onset. 

After ammonia is removed from the converter off-gases, the remaining gas stream enters an absorber where HCN is absorbed in cold water. The dilute HCN solution is stripped and fractionated by conventional means to produce HCN of 99.5% or higher purity. To avoid polymerization, the process streams in the HCN absorber and downstream equipment contain a small concentration of acid. All HCN recovery equipment is made of austenitic stainless steels to minimize corrosion problems and maintain product purity129. 

To minimize corrosion of stainless steel equipment all the processes use nitric acid solutions. Hence polyaminoacetic acid complexing agents such as DTPA are required to accomplish the critical problem of the separation of trivalent actinides from trivalent lanthanides 2). 

The Thorex wastes are not allowed to exceed 140 °F this minimizes corrosion of the stainless steel tanks. A series of three independent cooling coils has proved to be more than adequate for this purpose. 

Due to the corrosive nature of carboxylic acids, the oxidation reactor and associated peripherals must be constructed of corrosion-resistant materials, e. g., suitable stainless steels. As with all radical reactions, the surface to volume ratio of the reactor should be kept to a minimum to minimize radical recombination which always occurs on surfaces. 

In order to obtain the electro-osmotic current in the absence of an applied field [Eq. (2)], one may use two identical inert electrodes (i.e., not sustaining electrode reactions such as corrosion, or oxidation or redox reactions), which must be coimected to each other externally to complete the circuit in order to allow the electro-osmotic current, driven by the zeta potential alone, to occur. Identical electrodes (ideally, gold electrodes but more practically, inert graphite or stainless steel electrodes) are required to eliminate (ideally, but more practically to minimize) the galvanic battery effects and the associated electrode reactions. The total water removal during combined pressure and electro-osmotic dewatering is thus given by... 

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