Session: 18-02 Service of Gas Turbine Components - Life Assessment & Repair Processes

Paper Number: 81916

81916 - Serviced HGP Parts Assessment Using Microstructure-Based Models for New NovaLTTM16 Gas Turbine Validation 

NovaLT16 is a new high-efficiency gas turbine developed by Baker Hughes for mechanical drive and power generation applications in the 16MW market range.

 The Fleet Leader engine of this GT class underwent a planned maintenance stop which has been used to check the status of the most critical components and validate the engine design.

Hot Gas Path (HGP) components in particular have been object of a detailed assessment of their post-service conditions which included NDT inspections, dimensional measurements, air and water flow checks of cooling circuits. Selected components have been also destructively examined to check their microstructure condition and assess the level of service-induced base material and coating alteration.

The set of assessments carried out did not highlight any criticality in the engine overall condition or unexpected behavior with respect to design intent.

For High Pressure (HP) buckets a quantitative assessment of the service temperature has been also obtained leveraging a microstructure-based model specifically developed by Baker Hughes for bucket base material René N4, a first-generation single crystal superalloy. This model takes into account the time-temperature dependent alterations of the gamma/gamma’ material structure and namely the growth of the periodicity width lambda (λ), measured along the [001] lattice direction of the single crystal structure.

Presenting Author: Francesco Mastromatteo Baker Hughes - Nuovo Pignone Tecnologie

Presenting Author Biography: Francesco was born in Terni, Italy, in 1977.<br/>He graduated in Materials Engineering at University of Perugia in 2002 with a thesis titled &quot;Gamma’ coarsening kinetics modeling in Ni-base superalloy GTD111&quot;.<br/>In 2006 he obtained the Ph.D in Industrial Engineering at University of Perugia with a thesis titled &quot;Service temperature estimation models for residual life assessment of GT buckets and rejuvenation heat treatment development of Ni-base superalloys&quot;.<br/>In 2006 he joined GE Oil &amp; Gas Nuovo Pignone (now Baker Hughes) in Firenze, Italy, in the Materials &amp; Processes Engineering (MPE) Department. Since 2012 he is Senior Engineer for High Temperature Materials in the same organization.<br/>His areas of expertise include high temperature materials and coatings characterization, microstructure-based GT components life assessment models, GT components rejuvenation heat treatments and repair, investment casting process qualification for GT components.

Authors:

Francesco Mastromatteo Baker Hughes - Nuovo Pignone Tecnologie
Marco Romanelli Baker Hughes - Nuovo Pignone Tecnologie
Iacopo Giovannetti Baker Hughes - Nuovo Pignone Tecnologie
Chiara Cinelli Baker Hughes - Nuovo Pignone Tecnologie