High Temperature Oxidation and Hot Corrosion Behaviour of Detonation Gun Sprayed Al2O3 - 40%TiO2 Coating in Air and Salt on Inconel-600 at 8000 C under Cyclic Condition

Metals and alloys sometimes experience accelerated oxidation when their surfaces are covered with a thin film of fused salt in an oxidizing gas atmosphere at elevated temperatures. This is known as hot corrosion where a porous non-protective oxide scale is formed at the surfaces and sulphides in the substrate. Hot corrosion has been identified as a serious problem in high temperature applications such as in boilers, gas turbines, waste incinerations, diesel engines, coal gasification plants, chemical plants and other energy generation systems. It is basically induced by the impurities such as Na, V, S, K, and Cl, which are present in the coal or in fuel oil used for combustion in the abovementioned applications. The use of Ni-, Fe-, and Co- based super alloys in high temperature applications such as gas turbines, boilers, etc. is well known, and many more applications are still to be explored. Although the superalloys have adequate mechanical strength for such high temperature applications, they are prone to degradation by hot corrosion/high temperature oxidation during long term exposures. . Therefore, the superalloys need to be protected, however the protection system must be practical, reliable, and economically viable.