V94.3A Gas Turbine Lifetime Extension Clinic

Mechanical Dynamics & Analysis (MD&A) can extend the service life of gas turbine components whose OEM service limit has passed or whose configuration is no longer suitable to operate. Significant savings can be realized by opting for lower-cost repaired spares instead of new parts.

Elevated temperatures take a big toll on gas turbine components. Repair enhancements can extend a part’s life by slowing its degradation and extending its usable service life.

Formerly PW Powers Systems’ IGT division, the MD&A San Antonio Texas Service Center team have years of experience evaluating the life-limiting factors for gas turbine vanes and blades. Such factors include cracks, corrosion, wall thickness, and material condition.  Most crack limiting locations are found at the platform or shroud transition. Smaller percentages occur at the blade tip, the blade airfoil, or the root. Vane limiting factors are usually related to the wall thickness and material condition.

Platform degradation can be reduced in many ways: by operating in baseload only ( although dispatch conditions may prevent that from being a practical solution), by pursuing a robust platform weld repair program, by improving the integrity of the platform coating, and by making platform improvements.

Thermal mechanical fatigue cracks will eventually lead to platform failure. Design modifications often are required, incorporating a robust repair procedure. The life cycle enhancement process used by our experts exceeds OEM platform properties.

Our experts at the San Antonio Service Center combine years of experience with state-of-the-art equipment to deliver exactly the right solutions to your specific set of parts!

V94.3A4 2nd Stage Blade Extended to 75,000 EOH

A V94.3A4 2nd Stage Turbine Blade set had 50K EOH and operated through two service intervals, along with one repair performed by the OEM at 25K EOH.

Our San Antonio service center experts performed testing and evaluation on the blade set to determine if the hardware is deemed repairable and serviceable for another interval, as well as, evaluation of the previous repairs.

V94.3A4 2nd Stage Blade, gas turbine parts life extension

One 2nd Stage Blade tested in the as-received condition had an internal and external Coating Evaluation, along with a mechanical properties & metallurgical properties inspection.

The other 2nd Stage Blade was evaluated in the post-heat-treat condition with mechanical properties & metallurgical properties inspection, and then evaluation of metallurgical results. The heat-treated part was then evaluated for reparability.

The external TBC appeared in good condition. However, the blade tip has significant oxidation. This is most likely due to the weld wire selected during the previous repair.  All other inspections were normal.

gas turbine parts life extension

Our experts performed a pre-weld heat treatment, post-weld heat treatment, and a diffusion/aging combined cycle heat treat solution utilizing our vacuum heat treat furnace in our shop.

One heat-treated blade’s metallurgical properties were then evaluated and compared to the other blade in the as-received condition. The evaluation confirmed that the heat treatment process will heal and improve the gamma prime structure.

Based on all the evaluations performed on the two 2nd Stage turbine blades, our experts considered that the full set is a viable candidate for life extension to 75K EOH.

The measurements of the blade tip cap indicated that there was sufficient material to perform a successful weld build-up repair, so they removed most of the previous weld repair. Because of heavy oxidation on the blade tip, an oxidation-resistant alloy was used. Our weld repair procedure has demonstrated to provide excellent oxidation resistance during operation.

gas turbine parts life extension

A coating system consisting of a NiCoCrAlY applied by HVOF and a TBC topcoat was applied with our propriety coating. The V94.3A4 2nd Stage Blades’ lives were extended to operate to a total of 75K EOH.

Our San Antonio Service Center, or Gas Turbine Parts Service Facility, exemplifies best in service because of the deep experience in industrial gas turbine engineering and technology, repair techniques and equipment, and proven expertise on multiple frame gas components.

MD&A’s available Gas Turbine services range from full turnkey major inspections to rotor unstacking, gas turbine alignment, and control services. MD&A is a global full-service OEM alternative for services, parts, and repairs.

Call our MD&A San Antonio Service Center, or our Gas Turbine Parts Service Facility today at +1 (210) 256-5000.

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Proprietary Notice: WARNING – This document is the property of MD&A.  You may not possess, use, copy or distribute this document or any information in it for any purpose, including without limitation to design, manufacture or repair parts, or obtain FAA or other government approval to do so, without MD&A express written permission. Neither receipt nor possession of this document alone, from any source, constitutes such permission. Possession, use, copying or disclosure by anyone without MD&A express written permission is not authorized and may result in criminal and/or civil liability. EAR commercial/Civil or Dual- Use Notice: WARNING — This document contains technical data the export of which is or may be restricted by the Export Administration Act and the Export Administration Regulations (EAR), 15 C.F.R. parts 730-774. Diversion contrary to U.S. law is prohibited. The export, re-export, transfer or re-transfer of this technical data to any other company, entity, person, or destination, or for any use or purpose other than that for which the technical data was originally provided by MD&A, is prohibited without prior written approval from MD&A and authorization under applicable export control laws. EAR Export Classification: EAR 99


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