Nickel

NICKEL

Nickel is a silver-colored metal mainly used as an alloying element. It provides increased resistance to atmosphere and chemical corrosion and increases the strength of the alloy.

Properties

Nickel is resistant to strong alkalis and many acids. It has good resistance to corrosion and oxidation and is strong and tough.

Working Characteristics

Nickel can be fabricated using most of the commonly used processes, such as hot- and cold-rolling, extruding, bending, forging and spinning. It can be joined by some welding process, soldered, brazed, or joined with mechanical fasteners.

Production of Nickel

Several processes are used to produce nickel from the ore. The most recent is the Hybinette process developed in Canada. The ore is processed using the Bessemer process from which the molten goes to a cooling chamber. From here it is crushed and ground and magnetically separated. The result is a nickel-copper platinum alloy that is treated by the electrolysis process to separate the nickel, copper, and platinum.

Uses of Nickel

In addition to its use as an alloying element in ferrous and nonferrous metals, nickel is also an excellent material to use for electroplating and electroless plating. Electroplating is the process of depositing a coating of metal on another metal by electrolysis. Electrolysis is a method of plating a material by chemical means in which the piece to be plated is immersed in a reducing agent that, when catalyzed by certain materials, changes metal ions to metal, forming a deposit on the surface of the piece. Nickel is used in electric heating elements, lamp filaments, and plumbing fittings.

The nickel alloys of particular interest to the construction field are certain steels (low-nickel), stainless steels, Monel metals, aluminum, steel, and iron alloys, and nickel silvers. Each of these is important enough to merit discussion under a separate heading. Other alloys having important specialized applications but less used in construction field are heat-resistant alloys and electrical resistance alloys; thermal expansion alloys; and high nickel-copper, copper-nickel and coinage alloys. There are also special nickel alloys and super alloys for industrial, transportation, and chemical field.

Nickel Alloys

A major use for nickel is as an alloying element. The alloying of nickel to other metals provides increased ductility, corrosion resistance, strength, hardness, and toughness. Nickel alloyed to nonferrous metals improves electrical resistance and magnetism and helps control expansion.

Inconel 600 is a special nickel alloy containing about 75 percent nickel, 15 percent chromium, and 7 percent iron. Other nickel alloys include those used for electrical resistance coils, magnetic and nonmagnetic alloys containing iron, alloys designed to have a high coefficient of thermal expansion that are used in the production of glass, and copper-nickel alloys used for products exposed to marine conditions.

Monel is an alloy of approximately two-thirds nickel and one-third copper that has many uses in construction and industry.