Nickel alloy forgings and seamless rolled rings have been designed and developed over many decades for use in industries that require high temperature, corrosion resistance, and heavy wear properties. Nickel alloys are created with copper and aluminum, to form the Monel® group of alloys, with chromium, iron, and silicon to form the Inconel® group, and with molybdenum, chromium, iron, and tungsten to form the Hastelloy® group. 

Nickel alloy designations, such as 600, 625, 718, 725, 800, K500, or C276 reflect the chemistry and mechanical properties of the alloyed material.  Most alloys contain significant amounts of chromium.  Many others contain cobalt. Titanium, aluminum, columbium and vanadium are also added for improved heat resistance or for precipitation hardening effects.  

Alloys with resistance to extreme heat, harsh chemical environments, or saltwater conditions are often referred to as Super Alloys. Super alloys find many applications in aircraft, aerospace, chemical, marine, military, petroleum, and oil and gas exploration industries due to heat and scaling resistance, resistance to corrosive industrial media in processing and operating environments, atmospheric extremes, or sea water applications. Superalloys are expensive to melt, hot work, heat treat and cold work as required by the final shape and application. 

Nickel and its alloys may be forged, heat treated, welded and machined using conventional methods, but it should be noted that these alloys, many of which are applied because of their high temperature strength and corrosion resistance, must be handled with great care during hot working processes because they are subject to cracking during forging. Most nickel alloys benefit from an anneal after forging.  

Nickel alloys are used in nitric acid processing, and in some cases to resist sulfur-bearing gases. Hastelloy B, 65% nickel, 30% molybdenum, 5% iron, was developed for use in the hydrochloric acid industry, and can withstand the acid in high concentrations and at high temperatures. Hastelloys can also handle sulphuric acid. Nickel is alloyed with most of the elements encountered in steel manufacture, and is an important element in cryogenic engineering for use in low-temperature applications.

Heat treatment of nickel alloys normally involves a post-forge, high temperature anneal followed by air cool or water quench, depending upon the size and complexity of the part. This treatment may be followed by a precipitation treatment to give required properties.