Analysis of the causes of corrosion or erosion of blades
Posted: Wed Feb 12, 2025 9:31 am
4.1 Acid corrosion
In the initial condensation zone of the low-pressure cylinder, acidic substances in the steam (such as carbon dioxide, sulfur dioxide, etc.) accumulate in the condensate, resulting in a decrease in pH and corrosion of metal parts. This corrosion not only reduces the strength and service life of the blades, but also affects the overall performance and safety of the unit.
4.2 Oxygen corrosion
Dissolved oxygen is one of the main factors that causes oxygen corrosion. If the protective film on the blade surface (such as iron oxide film) is damaged, dissolved oxygen will react electrochemically with the metal matrix, causing iron ions to precipitate and corrode the material. In addition, factors such as pH, temperature, load, and flow rate greece number data will also affect the rate and extent of oxygen corrosion.
4.3 Water erosion
At low loads, liquid water droplets in the steam flow will hit the blade surface, causing water erosion. Water erosion not only destroys the blade surface structure, but also reduces its wear resistance, thereby accelerating the blade damage process.
5. Advantages of cobalt alloys
5.1 High temperature strength and oxidation resistance
Cobalt alloys have excellent high-temperature strength and oxidation resistance. This property allows cobalt alloy blades to withstand the high-temperature, high-pressure steam in steam turbines without deformation or damage. This advantage is critical to improving the operational efficiency and stability of steam turbines.
In the initial condensation zone of the low-pressure cylinder, acidic substances in the steam (such as carbon dioxide, sulfur dioxide, etc.) accumulate in the condensate, resulting in a decrease in pH and corrosion of metal parts. This corrosion not only reduces the strength and service life of the blades, but also affects the overall performance and safety of the unit.
4.2 Oxygen corrosion
Dissolved oxygen is one of the main factors that causes oxygen corrosion. If the protective film on the blade surface (such as iron oxide film) is damaged, dissolved oxygen will react electrochemically with the metal matrix, causing iron ions to precipitate and corrode the material. In addition, factors such as pH, temperature, load, and flow rate greece number data will also affect the rate and extent of oxygen corrosion.
4.3 Water erosion
At low loads, liquid water droplets in the steam flow will hit the blade surface, causing water erosion. Water erosion not only destroys the blade surface structure, but also reduces its wear resistance, thereby accelerating the blade damage process.
5. Advantages of cobalt alloys
5.1 High temperature strength and oxidation resistance
Cobalt alloys have excellent high-temperature strength and oxidation resistance. This property allows cobalt alloy blades to withstand the high-temperature, high-pressure steam in steam turbines without deformation or damage. This advantage is critical to improving the operational efficiency and stability of steam turbines.