Nickel Alloys: What Do They Stand For?
Nickel is added to high chromium stainless steel to create a class of corrosion and heat resistant steels where the tendency of nickel to form austenite is responsible for toughness and high strength at both high and low temperatures. Nickel also improves resistance to oxidation and corrosion. It increases toughness at low temperatures when added in smaller amounts to alloy steels.
Nickel and nickel alloys are used for a wide variety of applications, including aircraft gas and steam turbines, medical applications, nuclear power systems, and of most interest to Broder Metals Group, oil, chemical and petrochemical industries.
Nickel is a very versatile alloy material element, and there are many classifications that nickel alloys can be classified into. One of the most common classifications is as follows:
Commercially Pure/Low Alloy Nickels – Nickel is supplied in powder, pellet, or anode forms. These materials are very high density, offering magnetic and electronic property capabilities. They also offer excellent corrosion resistance along with reasonable thermal transfer characteristics.
Nickel-Copper alloys – possess excellent corrosion resistance in reducing chemical environments and in sea water, where they deliver excellent service in nuclear submarines and various surface vessels. By changing the various proportions of nickel and copper in the alloy, a whole series of alloys with different electrical resistances can be created. Prime amongst these alloys are Alloy 400 and Alloy K500.
Nickel-chromium – provide higher strength and resistance to elevated temperatures. Prime alloys are Alloy 600, Nimonic alloys including N80a, Alloy X750. Alloy 718, Alloy 625. Alloy C-22, and Alloy C-276.
Iron-Nickel-Chromium Alloys – Used in high-temperature petrochemical environments, where sulphur-containing material are cracked into component distillate parts. Prime alloys in this class are Alloy 800 / 800HT. Alloy 825, Alloy 925
Controlled-expansion alloys – offer high strength and low coefficient of thermal expansion, for example Alloy 902, 903, 907, and 909.
Nickel-lron Low-Expansion Alloys – developed for the lamp and electronics industries where glass-to-metal seals in sealed environments are important. Prime alloys are Alloy 42 and Alloy 426.
Soft Magnetic Alloys – these nickel-iron alloys also offer magnetic permeability properties used principally in switchgear and for direct current motors and generators.
Welding Alloys – additions of aluminium, titanium, magnesium, and other elements are made to the filler metals and welding electrodes to provide better weld effects and to overcome any hot-short cracking and malleability problems.