Cement kiln dust induced corrosion fatigue damage of gas turbine compressor blades – A failure analysis

• One of the first stage broken blades of a compressor was failure analyzed.
• The power plant located near a cement company and an oil refining company.
• Hence, the inlet air of compressor had large amounts of Cl and S compounds.
• Therefore, the corrosion pits were formed on the compressor blade surface.
• Corrosion pits acted as stress concentration sites for fatigue fracture.

Compressor of one of the gas turbines installed in a power plant was stopped under emergency conditions. Primary investigation showed that almost all of the first stage blades and some of the next stages were severely damaged. In this study, one of the first stage broken blades was failure analyzed. The results showed that the corrosion pits were formed on the compressor blade surface due to the presence of Cl and S elements in the compressor inlet air. Since the power plant located in the vicinity of a cement company and also an oil refining company, the inlet air of compressor had large amounts of Cl and S containing compounds. The corrosion pits acted as stress concentration sites, and facilitated fatigue crack initiation and propagation, leading to final fracture of the blades.