Nickel and alloy
Nickel is a versatile, highly corrosion resistant element that will alloy with most metals. Due to its corrosion resistance, nickel is used to maintain product purity in the processing of foods and synthetic fibers. It is highly resistant to various reducing chemicals and is unexcelled in resistance to caustic alkalies. In addition, nickel has good thermal, electrical and magnetostrictive properties. Relatively high thermal conductivity of this metal has lead to its frequent use for heat exchangers
Commercially pure or low-alloy nickel may contain very small amounts of alloying elements to absolutely none. By contrast nickel alloys contain significant amounts of added elements. Nickel and nickel alloys are both non-ferrous metals that are useful in a range of applications, most of which involve corrosion resistance and/or heat resistance.
Inconel 718 is a nickel-chromium-molybdenum alloy designed to resist a wide range of severely corrosive environments, pitting and crevice corrosion. This nickel steel alloy also displays exceptionally high yield, tensile, and creep-rupture properties at high temperatures. This nickel alloy is used from cryogenic temperatures up to long term service at 1200 F. One of the distinguishing features of Inconel 718s composition is the addition of niobium to permit age hardening which allows annealing and welding without spontaneous hardening during heating and cooling. The addition of niobium acts with the molybdenum to stiffen the alloys matrix and provide high strength without a strengthening heat treatment. Other popular nickel-chromium alloys are age hardened through the addition of aluminum and titanium. This nickel steel alloy is readily fabricated and may be welded in either the annealed or precipitation (age) hardened condition. This superalloy is used in a variety of industries such as aerospace, chemical processing, marine engineering, pollution-control equipment, and nuclear reactors.
Chemical processing
Aerospace
Liquid fuel rocket motor components
Pollution-control equipment
Nuclear reactors
Cryogenic storage tanks
Valves, fasteners, springs, mandrels, tubing hangers
Well head completion equipment and blow out preventers (BOPs)
Gas turbine engine parts
Good mechanical properties C tensile, fatigue and creep-rupture
Yield tensile strength, creep, and rupture strength properties are exceedingly high
Highly resistant to chloride and sulfide stress corrosion cracking
Resistant to aqueous corrosion and chloride ion stress corrosion cracking
High temperature resistant
Age-hardenable with a unique property of slow aging response that permits heating and cooling during annealing without the danger of cracking.
Excellent welding characteristics, resistant to postweld age cracking
