Oxidation and hot corrosion behaviour of Nimonic-75 superalloy

Experiments were carried out to study the oxidation and hot corrosion behaviour of Nimonic-75 superalloy in the unwelded and welded conditions in the temperature range of 700-1000°C. The salt mixture used for hot corrosion studies was 90% Na2SO4 and 10% NaCl. While the oxidation attack increased with temperature, the hot corrosion attack dropped in the higher ranges of temperature. This is attributed to vapourisation of the salt mixture. The weight gain due to oxidation and hot corrosion followed a power function the exposure time.