Photomicrograph showing bond coating oxidation
Photomicrograph showing bond coating degradation
Photograph of a corrosion-attacked area on a Frame 5 blade after 40,000 hours of service
To evaluate the life of components, it is essential to identify the probable failure modes for a given component. The possible failure modes for hot section components include thermal mechanical fatigue (TMF), hot corrosion, creep, and coating oxidation and degradation.
Engineers at Southwest Research Institute (SwRI) examine the parts using state-of-the-art laboratory facilities. They examine hot section parts failed in service and identify the most probable cause of failure.
Life Evaluation Methodology
In gas turbines, the life and integrity of the coatings, applied to protect the components from environmental attack and degradation, govern the life and maintenance intervals of hot section components. SwRI has developed state-of-the-art coating and TMF life prediction methods for several substrate/coating systems. The TMF model has been calibrated with service experience and can be used to predict the life of a specific coating on turbine blades in service.
Through an industry consortium program, GTD LIFE software was developed to calculate the remaining life of GE MS5002 engine first-stage buckets. This software is available to turbine users.
Life Management System Flow Diagram
Flow diagram shows the tasks required to develop a life management system for determining the life of gas turbine components. SwRI is one of the few organizations capable of performing each step in the development of these systems.
The images above show in-service degraded coating of a 7FA blade (first
image) and a 9FA blade (second image) after 21,000 hours of service.
TMF model validation for Frame 7FA and 9FA blades. Model prediction is in good agreement with
SwRI can offer you a full range of capabilities and experience in gas turbine technology including becoming an extension of your engineering department.
Contact us for more information about our gas turbine life evaluation capabilities, or how you can contract with SwRI.