Revitalize Your Gas Turbine Blades with Liburdi's FSR® Process

Before and after repair of a gas turbine blade including microstructure

Article Summary

  • Liburdi Turbine Services Full Solution Rejuvenation® (FSR®) process restores gas turbine blades to "like new strength" and extends their service life beyond OEM limitations.
  • Normal wear and tear, including exposure to high temperatures and pressures, lead to a progressive loss of creep strength in gas turbine blades, pushing them into the risk zone. FSR® reverses thermal aging damage, resolving creep damage and stress-related voids in superalloys.
  • FSR® involves a special pressure treatment called Hot Isostatic Pressing (HIP) to collapse creep voids and a series of unique heat treatments to restore strengthening precipitates. This process eliminates aging and creep as retirement causes, allowing gas turbine operators to extend equipment life and avoid frequent turbine blade replacements, leading to significant cost savings.

Liburdi Turbines Services developed the unique Full Solution Rejuvenation® (FSR®) process, which renews gas turbine blades to "like new strength." FSR extends the service life beyond OEM limitations.

Under normal conditions, the strength of the blade material depletes over time due to stress and temperature. Normal wear and tear diminish the gas turbine blade's strength below safe minimum levels into the risk zone. Usually, blades retire from service after two service cycles, as shown in Figure 1.

Graph showing Progressive loss of gas turbine blade creep strength with service time.
Figure 1: Progressive loss of gas turbine blade creep strength with service time.

Adding FSR® to Liburdi's complete repair scope restores alloy strength beyond the safe minimum level. This process can be repeated, extending the value of expensive turbine blades.

Before and after service pictures of gas turbine blades which underwent FSR heat treatments
Figure 2: FSR® reverses thermal aging damage in superalloys.

The two leading causes of turbine blade metallurgical degradation are heat and stress. Exposure to high temperatures softens the metal ("over-aging"), and exposure to high pressures in conjunction with heat causes creep (a condition where metal distorts on a microscopic level). The blade will eventually crack and fracture if these mechanisms continue, leading to irreversible damage and high-cost blade replacements.

Figure 3 showcases the microscopic integrity of blades in three states, illustrating how FSR resolves creep damage. The left side of the figure displays the microstructure of a brand-new blade. After service, the microstructure degrades the metal, leading to creep damage (center frame). The frame on the right of Figure 3 shows how a blade treated with FSR® dramatically improves the blade's microstructure, extending the part's life.

Microstructure of gas turbine blades from brand new to service run then recieving FSR® treeatment to reverse stress damage in superalloys.
Figure 3: FSR® reverses stress damage in superalloys.

Additionally, microscopic movements cause small voids in the alloy after service. FSR® reverses this degradation and re-densifies the alloy to its original condition.

There are two main phases in the FSR® process; the first involves a special pressure treatment called Hot Isostatic Pressing (HIP), which is applied to collapse creep voids accumulated in the blade. The second is a series of unique heat treatments used to dissolve and regrow the strengthening precipitates back to their original size, restoring the part's initial strength.

Chart showing part service time and how Full Solution Rejuvenation increases gas turbine part life
Figure 4: Turbine blade rejuvenated creep strength with service time

Liburdi's FSR® process effectively eliminates aging and creep as a part's retirement cause when applied at regular intervals. FSR® entitles turbine operators to extend the life of their turbines by keeping their machines running optimally and bypassing the need to replace turbine blades frequently.

Your organization can save hundreds of thousands in replacements and repairs by utilizing Liburdi's FSR® process to strengthen and extend the life of your equipment.

Are you interested in learning how FSR® can help your organization? Contact Jeff Chapin (US office) at jchapin@liburditurbine.com or Robert Tollett (Canadian office) rtollett@liburdi.com.