Analysis of Turbine Blade Fracture
Turbine blades play a vital role in the operation of many power plants. As such, being able to identify the causes of failure and analyzing why blades fail are important for maintaining the safe running of turbine components. In this paper, the causes of blade fractures and the associated countermeasures are discussed.
In most cases, turbine blades fail due to fatigue. Fatigue failure is caused by the repeated cycles of alternating stresses and forces acting on the turbine blades. At high loads, the material of the blades can become brittle and eventually fail due to fatigue. It is important to know if the stresses and forces which caused the failure were within design limits or not. If they are not, overstressing of the blade can have caused the failure. Also, if the stresses and forces acting on the blade were above design limits, improper design may have led to its failure.
Turbine blade fractures can also be caused by metallurgical flaws, such as impurities and/or imperfections in the metal. Metallurgical flaws can give rise to microscopic weak spots in the blade. Under some circumstances, these weak spots can become stressed and eventually fail due to fatigue. It is essential to analyse the fracture surfaces in order to identify the causes of blade fracture.
Blade failure due to corrosion is also common. The corrosion process is complex and can be caused by a number of environmental factors, such as water, dust or even small particles in the air. Corrosion of turbine blades can lead to a weakening of the material and can result in blade failure.
In order to prevent or minimise blade fractures, it is important to detect any damage or wear of the blades before they fail. This can be done through inspections of the turbine blades and monitoring of the operating conditions of the turbine. Blade replacement should be done in a timely manner where necessary, and any necessary rework should be carried out with great care.
Additionally, the operating temperature of the turbine must be kept within optimal levels, as an excessively high temperature could lead to blade failure. Also, turbine blades must be designed in a manner that can effectively deal with vibrations, as this can give rise to excessive stresses and forces on the blades.
In conclusion, blade fractures can often be attributed to fatigue, metallurgical flaws, corrosion or improper design. To reduce the risk of blade failures, it is important to inspect and monitor blades regularly, as well as maintain optimum operating conditions. Appropriate design of turbine blades can also help to minimise the risk of failure due to fatigue and vibration.
