Nickel based alloys

Superalloys, also known as heat-resistant alloys or high-temperature alloys, are classified into different groups. Nickel based and cobalt based make up part of them. Nickel based superalloys have the ability to maintain high creep strength, oxidation and corrosion resistance at high service temperatures (up to about 1100°C). Regarding hardfacing applications, our nickel based superalloy cored wires are 100% compatible with open-die forging applications (such as shafts, presses or hammers).
There are two metallurgical reasons as to why these nickel based superalloys perform so highly. First, elements such as molybdenum, tungsten, cobalt and chromium have been proven to strengthen solid solutions, and will favour the high temperature strength of the welding deposit.

Second, elements such as titanium and aluminium will have an age hardening effect by forming a face-centred cubic structure, providing maximum strength through precipitation.
Several studies involving nickel based superalloys have shown that these welding deposits can be difficult to work with because they have a tendency to crack during welding. By controlling the chemical analysis of our cored wires (e.g. aluminium to titanium ratio), Welding Alloys helps customers ensure they stay in the safest zone, whilst also achieving the expected hardfacing deposit.

Robotic cladding of a valve using STELLOY 21-G.

(Click image to enlarge)

(Click image to enlarge)