Nickel-iron alloys applications

Nickel-iron alloys have a number of important applications that are derived from such special physical properties as their unique magnetic characteristics in the regions of 35, 50 and 80% nickel and from their abnormally low thermal expansion in the region of 36-50% nickel. Although not specifically used as corrosion-resistant materials, their high resistance to attack from many common environments is of benefit in their specialised applications. 

Nickel-iron alloys have specific physical properties, such as magnetic response or low thermal expansion, giving them niche applications (e.g., for glass to metal seals and linkages that require little or no thermal expansion). 

This coating has the disadvantage of forming red rust when immersed in water consequently nickel-iron alloy coating is suitable for use in mild atmospheres only. Typical applications include kitchenware and tubular furniture. 

Sacrificial metal coatings are very effective in preventing corrosion in areas where dust tends to collect. Nickel-iron alloy coatings, developed as an alternative to nickel coatings, find application for mild interior service. 

Unlike the PCB world where the basis metals used are inherently solderable, such as copper or nickel, the component world deals in basis metals that are non-solderable such as stainless steel or brass (solderable with fluxes not typically found in the electronics industry), marginally solderable (such as Alloy 42—a nickel iron alloy), to easily solderable (such as C194 copper alloy). This fact needs to be realized when designing with or choosing a metal or alloy for a given component and the simple question, Will this part solder if the surface finish application or quality is marginal needs to be asked. If the answer is no, as when using stainless... 

Gilbert, P. T., Corrosion Resisting Properties of 90/10 Copper Nickel Iron Alloy with Particular Reference to Offshore Oil and Gas Applications, British Corrosion Journal, (1979). 

The primary uses for nickel are as an additive to make stainless steel, cupronickel and nickel-iron alloys, for electroplating other metals, and in batteries. Electronic applications include alloys with iron (42% nickel) that are used as leadframe material in ceramic packages for semiconductors, and as plating on component leads (terminations). Nickel is often plated onto copper to prevent copper from leaching into gold plating or melted solder. 

The composition of this alloy (54% nickel, 15% molybdenum, 15% chromium, 5% tungsten and 5% iron) is less susceptible to intergranular corrosion at welds. The presence of chromium in this alloy gives it better resistance to oxidizing conditions than the nickel/molybdenum alloy, particularly for durability in wet chlorine and concentrated hypochlorite solutions, and has many applications in chlorination processes. In cases in which hydrochloric and sulfuric acid solutions contain oxidizing agents such as ferric and cupric ions, it is better to use the nickel/molybdenum/ chromium alloy than the nickel/molybdenum alloy. 

The successful application of nickel-chromium-iron alloys as structural components of industrial furnaces and as chambers and containers in chemical processing under conditions of exposure involving sulphur substantiates their good resistance to this form of corrosion. These materials are used for service temperatures in the range 750-1 200°C, the upper limit of serviceability being determined largely by the chromium content of a particular alloy. Results of corrosion tests (Table 7.24) on cast nickel-... 

Recent industrial experience for alloys in waste incineration plants has indicated the superiority of nickel-base alloys compared with iron-base and iron-containing alloys as would be expected from the previous discussion of the volatility of chlorides. Nickel-base alloys with no addition of iron and relatively high chromium contents have significantly improved performance in these applications (see Tables 7.33 and 7.34.) . 

Replacing some of the nickel with iron produces a family of alltws with intermediate corrosion resistance between stainless steels and the Ni-Cr-Mo alloys. Alloys such as Incoloy 825 and Hastelloy G-3 and G-30 are in this family. Incoloy 825 has 40 percent Ni, 21 percent Cr, 3 percent Mo, and 2.25 percent Cu. Hastelloy G-3 contains 44 percent Ni, 22 percent Cr, 6.5 percent Mo, and 0.05 percent C maximum. These alloys have extensive applications in sulfuric acid systems. Because of their increased nickel and molybdenum contents they are more tolerant of chloride-ion contamination than are standard stainless steels. The nickel content decreases the risk of stress-corrosion cracking molybdenum improves resistance to crevice corrosion and pitting. Many of the nickel-based alloys are proprietary and are coverecf by the following specifications ... 

Iron-nickel alloys, 17 101 Iron-nickel martensitic alloys, 23 308 Iron(II) nitrate hexahydrate, 14 541 Iron(III) nitrate hexahydrate, 14 541 Iron ore(s), 14 494-497 agglomeration of, 14 497 beneficiation of, 14 495-497 economic aspects of, 14 523 high- and low-grade grade, 14 495-496 reduction of, 14 510-513 sources of, 14 494-495 U.S. consumption of, 14 527t Iron ore pelletizing, smectites application, 6 697t, 698... 

Nickel-chromium alloys, 77 100-101 dental applications, 8 308, 310 Nickel-chromium-iron alloys, 73 519, 522 Nickel-chromium-molybdenum alloy C, in galvanic series, 7 805t... 

Nickel—Iron and Cobalt—Iron Alloys. Sdenium improves the machinability of Ni—Fe and Co—Fe alloys which are used for dectrical applications. Neither sulfur nor tellurium are useful additives because these dements cause hot brittleness. The addition of 0.4—0.5% sdenium promotes a columnar crystal structure on solidification, doubling the coercive force of cobalt—iron—titanium alloy permanent magnets produced with an equiaxial grain structure. 

Inconel alloy 925 —An age-hardenabte nickel-iron-chromium alloy providing high strength up to 540°C i1000 F), Developed for use in gas production applications, such as tubular products, tool joints, and equipment for surface and downhole hardware in gas industry,... 

In addition to the metals listed above, many alloys are commercially electroplated brass, bronze, many gold alloys, lead—tin, nickel—iron, nickel—cobalt, nickel—phosphorus, tin—nickel, tin—zinc, zinc—nickel, zinc—cobalt, and zinc—iron. Electroplated alloys in lesser use include lead—indium, nickel—manganese, nickel—tungsten, palladium alloys, silver alloys, and zinc—manganese. Whereas tertiary and many other alloys can feasibly be electroplated, these have not found commercial applications. 

Cryogenic service is usually defined as temperatures below -100°C (-150°F). Properties of some cryogenic fluids are listed in Table 2.73. Valve materials for operation at temperatures down to -268°C (-450°F) include copper, brass, bronze, aluminum, 300-series stainless steel alloys, nickel, Monel, Durimet, and Hastelloy. The limitation on the various steels falls between 0° and -150°F (-17 and -101°C), with cast carbon steel representing 0°F (-17°C) and 3.5% nickel steel being applicable to -150°F (-101°C). Iron should not be used below 0°F (-17°C). 

In recent years, a number of especially resistant iron alloys have appeared on the market and have been rapidly adopted. They are, essentially, nickel-chrome-iron alloys, usually containing very little carbon. These alloys are very resistant to acids and alkalis and are used chiefly where high resistance to chemicals is the deciding factor. The different VA-steels, and the English S-80, are examples of these alloys which vary in composition depending on the particular application. These alloys withstand concentrated nitric acid, and other acids, except hydrochloric, scarcely attack them at all. They are especially important in modem high pressure syntheses. Potassium hydroxide scarcely attacks these alloys even in fusion mixtures, and they are quite satisfactory, therefore, for indanthrene fusions. (Nickel is also suitable in this particular case.)... 

Nickel and its alloys are extensively used in electrochemical applications due to its good corrosion resistance. In battery applications, nickel is used as the positive electrode in nickel-cadmium, nickel-iron, nickel-zinc, and nickel-hydrogen batteries, and as anodes in fuel cells, electrolyte cells and electro-organic syntheses . Because of the importance of nickel in battery applications, electrochemical properties of nickel have been studied for more than IOC years since 1887 when Dun and... 

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