Properties and Applications Superalloys Properties and Applications

Contents Classification of Superalloys Properties Applications Application in Oil- Gas sector Turbine blades made up of nickel superalloy

Classification of Superalloys These alloys have austenitic FCC structure which have base alloying element of nickel, cobalt and iron. Further they are classified on the basis of pre-dominant element present in it. Alloying elements are Fe, Co, Ni, Cr, W (tungsten), Mo (molybdenum), Nb (niobium) and Ta (tantalum). Iron based alloys: 9-38 % nickel 15-22 % chromium 32-67 % iron Common type of Iron based alloy is Incoloy series.

Cobalt based alloys: Up to 35% nickel 19-30 % chromium 30-65 % cobalt Cobalt based alloys can retain their strength at high temperature but they are not as strong as nickel based alloys.

Nickel based alloys: 38-76% nickel Up to 27 % chromium Up to 20 % cobalt. Some of the common type of nickel based alloys are Nimonic, Hastelloy and Inconel. These are the most common types of Superalloy which are widely used in turbine blades

Properties of Superalloys Excellent mechanical strength and wear resistance at high temperature. Resistance to corrosion and oxidation at very high temperature. Good surface stability.

Applications of Superalloys In Aerospace : blades of turbines and in jet/rocket engines. In Marine : wide use in Submarines. In Chemical processing industries. Heat exchanger tubing Industrial gas turbines Nuclear Reactors

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