Why do gas turbine blades fail?
Why do gas turbine blades break?
Why do gas turbine blades fail?
Gas turbine blades are one of the most sensitive and important parts inside the turbine,
and the slightest failure in them can cause reduced efficiency, downtime, and very high repair costs.
But the main question is why do gas turbine blades fail at all?
1. Increased temperature and thermal shock (Thermal Stress)
Gas turbine blades operate in extremely hot conditions; that is, temperatures above 1000 degrees.
This intense heat causes the metal to undergo thermal stress.
When the temperature suddenly rises or falls, the blades gradually develop tiny cracks, which is called Thermal Fatigue.
What is the cause of this problem?
Frequent turning the turbine on and off Lack of proper cooling Using weak or old materials in the construction of the blade
2. Creep at high temperatures
One of the most dangerous problems with gas turbine blades is the Creep phenomenon.
Creep is the slow deformation of a blade under high pressure and temperature. This usually occurs gradually,
but it is quite visible and measurable.
What are the signs of creep in blades?
The blade length is slightly elongated The clearance between the blade and the housing changes Efficiency decreases When creep increases,
the blade may hit the body during rotation, causing a complete fracture
3. Corrosion & Oxidation
The ingress of particles, moisture, salt or environmental contaminants causes corrosion of the blade surface.
This corrosion causes the thermal and protective coatings to be destroyed and the base metal to be exposed to damage.
Common causes of blade corrosion include:
Operating the turbine in coastal environments Low fuel quality Inefficient air intake filters Chemical leakage Blade
surface corrosion directly reduces the strength of the part and increases the likelihood of cracking or breaking
4. Mechanical vibration (Vibration & Mechanical Fatigue)
Vibration is one of the important factors in the failure of gas turbine blades.
If the blade is unbalanced for any reason, it receives small impacts with each revolution and gradually suffers from metal fatigue (Fatigue).
Causes of sudden vibration Foreign object entry (FOD) Uneven wear of the edges Rotor imbalance Incorrect installation of new blades
5. Foreign object damage
One of the most severe and costly causes of blade failure is the collision of foreign objects with them.
Even a small screw, pebble, bird or any other object can destroy a blade at a few thousand revolutions per minute.
Summary
Why do gas turbine blades fail?
From high heat to creep, corrosion, vibration and foreign body impact, all of these factors cause gas turbine blades to crack,
wear or break. Understanding these causes helps to increase blade life and reduce repair and downtime costs by regular inspection,
selecting the right coating, temperature control and standard fuel.
Finally, contact Kian Turbo tec to repair gas turbine.
