Akademik Veri Yönetim Sistemi
JOURNAL OF POLYTECHNIC-POLITEKNIK DERGISI, 2025 (ESCI, TRDizin)
This study evaluated the physical and chemical changes that turbine blades are exposed to under operating conditions and their effects on the material. Within the scope of the study, the amount of corrosion and wear that occurred during the durability/operational life of a turbine blade and its coating used for 25 years in a Thermal Power Plant, and an original turbine blade made of the same material that has never been used were comparatively examined. This research contains significant findings in evaluating the suitability of the existing material and coating for the longer life of turbine blades and obtaining ideas for changes to be made to the coating in terms of resistance to physical and chemical conditions. The turbine blade examined in the study was determined to be coated with Co-based material (containing Cr, Mo, Ni, Mn) using the thermal metal spray coating method. AgCuZn-based bond coating was applied to the coating and the substrate. After 25 years of service with an average energy production of 69,466,700 MWh, the turbine blade was removed from the turbine and examined for corrosion and erosion damage analysis. In the experimental study, chemical and dimensional measurements, optical microscopy, SEM, and EDS measurements were carried out due to the metallographic preparation of the samples. XRD performed structural analysis, and hardness testing was used to determine the mechanical properties and life of the samples. As a result of the investigations, it was determined that the turbine blade was subjected to corrosion, erosion, and corrosive erosion; the coating on the surface was completely worn locally, and there was a cross-sectional reduction due to wear (corrosive and erosive) at the blade tips. The coated parts were more resistant to erosive and corrosive effects. When comparing the coating wear with the base material wear, the level of wear is more clearly seen in the transition area between the coated area and the base material.. It has been observed that corrosion and erosion cause abrasion together.