Hot Corrosion Behavior of Superalloy in Different Corrosive Environments
- 1 Department of Mechanical Engineering, Universiti Teknologi PETRONAS, Tronoh, Malaysia
- 2 Department of Mechanical Engineering, Universiti Teknologi PETRONAS, Tronoh, Malaysia
- 3 Department of Mechanical Engineering, Universiti Teknologi PETRONAS, Tronoh, Malaysia
- 4 Centre for Intelligent Signal & Imaging Research, Universiti Teknologi PETRONAS, Tronoh, Malaysia
Abstract
Hot corrosion is a serious problem in aircraft, marine, industrial and land-base gas turbines. To obviate these problems, superalloy superfer 800H (Midhani grade) is one of the prominent materials for the high temperature applications. The present work investigates hot corrosion behaviour of superfer 800H exposed to two different molten salt environments Na 2 SO 4 + 60% V 2 O 5 and Na 2 SO 4 + 5% V 2 O 5 + 5% NaCl respectively, at 900<sup>o</sup>C under cyclic conditions. The weight change measurements made on during the experiments are used to determine the kinetics of hot corrosion. It is observed that the formation of scale rich in Cr 2 O 3 , NiO and spinel NiCr 2 O 4 has contributed for the better hot corrosion resistance of superfer 800H. Inspection for 10, 20, 35 and 50 cycles reveals that after 10 cycles Crack has been initiated in the scale and it is clearly visible in the presence of NaCl salt. On subsequent cycles, crack propagates perpendicular to surface and as it encounters inclusions.
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