Mechanical Properties in GTD-111 Alloy in Heavy Frame Gas Turbines

2018 ◽  
Author(s):  
John R. Scheibel ◽  
Rajeev Aluru ◽  
Hans van Esch
Keyword(s):  
Mechanical Properties ◽  
Gas Turbines ◽  
Base Material ◽  
Partial Solution ◽  
Heat Treatments ◽  
Hot Gas ◽  
Operating Environments ◽  
Industrial Gas Turbines ◽  
Full Solution ◽  
Temperature Time

Nickel-based superalloys are extensively used in manufacturing hot gas path components in industrial gas turbines used for power generation. Specifically, GTD-111 DS is one of the widely used alloys used in manufacturing the hot gas path rotating components. These components are subjected to extreme operating environments resulting in creep, oxidation, and fatigue of the components during operation. After continued operation, these damage modes need to be repaired and the components go through extensive repair processes, which include several heat treatments to recover the mechanical properties of the base material (GTD-111 DS) lost during operation. The heat treatments used during repair by the different repair vendors can vary widely in terms of temperature, time and the sequence as well. This study focuses on understanding the differences in the effects of the heat treatments (partial solution, full solution, HIP and full solution) to the base material in terms of microstructure-mechanical property relationships. Results indicate that HIP and full solution resulted in refined microstructures and improved mechanical properties compared to the heat treatments involving partial solution or full solution only. Microstructuremechanical property relationships suggest that components that need to be repaired beyond OEM recommended repair intervals benefit from the HIP and full solution heat treatments.

Repair Techniques for Hot Gas Path Components in Industrial Gas Turbines

1982 ◽  
Author(s):  
J. S. Dodgson
Keyword(s):  
Gas Turbines ◽  
Heat Treatments ◽  
Hot Gas ◽  
Industrial Gas Turbines ◽  
Repair Techniques

The methods used to repair turbine components from Industrial gas turbines are reviewed and explained. Particular reference is made to cleaning, heat treatments, welding, brazing, machining, coatings and inspection.

Deformation and Fracture Behaviors in the Freestanding APS-TBC - Effects of Process Parameters and Thermal Exposure

2007 ◽  
Vol 353-358 ◽  
pp. 1935-1938 ◽  
Author(s):  
Yasuhiro Yamazaki ◽  
T. Kinebuchi ◽  
H. Fukanuma ◽  
N. Ohno ◽  
K. Kaise
Keyword(s):  
Mechanical Properties ◽  
Process Parameters ◽  
Gas Turbines ◽  
Thermal Exposure ◽  
Substrate Material ◽  
Process Variables ◽  
Microstructural Investigation ◽  
Deformation And Fracture ◽  
Industrial Gas Turbines ◽  
Tbc Systems

Thermal barrier coatings (TBCs), that reduce the temperature in the underlying substrate material, are an essential requirement for the hot section components of industrial gas turbines. Recently, in order to take full advantage of the potential of the TBC systems, experimental and analytical investigations in TBC systems have been performed. However there is a little information on the deformation behavior of the top coating. In addition, the effects of the thermal exposure and the process parameters on the mechanical properties of the top coating have never been clarified. From these backgrounds, the effects of the process variables in APS and the thermal exposure on the mechanical properties were investigated in order to optimize the APS process of top coatings. The experimental results indicated that the mechanical properties of the APS-TBC, i.e. the tensile strength and the elastic modulus, were significantly changed by the process variables and the long term thermal exposure. The microstructural investigation was also carried out and the relationship between the mechanical properties and the porosity was discussed.

GT26 2006 Turbine Stage 1 Blade Reconditioning Development and Qualification at Ansaldo Repair Centre

2021 ◽  
Author(s):  
Elisa Mela ◽  
Federico Fignino ◽  
Alessio Gabrielli ◽  
Paola Guarnone ◽  
Emanuele Porro ◽  
...  
Keyword(s):  
Gas Turbines ◽  
Base Material ◽  
Repair Process ◽  
Market Demand ◽  
Technology Improvement ◽  
Industrial Gas Turbines ◽  
And Performance ◽  
Stage 1 ◽  
Welding Procedure ◽  
Repair Techniques

Abstract The evolution of industrial gas turbines towards increased efficiency and performance requires even higher operating temperatures for the engines. In order to remain competitive in the market, OEM companies continuously need to develop maintenance programs and repair technologies able to extend the life of these components as much as possible. The repair technology improvement is fundamental to reduce scrap rates and maintenance costs to be competitive on the market. The Ansaldo Repair Centre answers to this market demand by providing advanced and competitive repair techniques and an increasing broad repair portfolio to its customers. This paper describes the steps and approach to determine the repair process of GT26 LPT Blade 1 in order to allow the component to run another service interval. The base material status and the indication found after service was used as the foundation for a development of a dedicated repair sequence from stripping, to suitable heat treatments, to enhanced repair technique to recoating of the blade. Particular attention was paid to the most damaged area, for which a particular welding procedure including an optimized filler material has been applied for the rebuilding of the tip and platform zones as well as for the restoration of the unique tip closing features.

Repair of Advanced Gas Turbine Blades

2005 ◽  
Author(s):  
Julie McGraw ◽  
Reiner Anton ◽  
Christian Ba¨hr ◽  
Mary Chiozza
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
High Efficiency ◽  
High Reliability ◽  
Turbine Blades ◽  
Base Material ◽  
Operating Experience ◽  
Cost Effective ◽  
Directionally Solidified ◽  
Hot Gas

In order to promote high efficiency combined with high power output, reliability, and availability, Siemens advanced gas turbines are equipped with state-of-the-art turbine blades and hot gas path parts. These parts embody the latest developments in base materials (single crystal and directionally solidified), as well as complex cooling arrangements (round and shaped holes) and coating systems. A modern gas turbine blade (or other hot gas path part) is a duplex component consisting of base material and coating system. Planned recoating and repair intervals are established as part of the blade design. Advanced repair technologies are essential to allow cost-effective refurbishing while maintaining high reliability. This paper gives an overview of the operating experience and key technologies used to repair these parts.

Clearance Reduction and Performance Gain Using Abradable Material in Gas Turbines

2008 ◽  
Author(s):  
Iacopo Giovannetti ◽  
Manuele Bigi ◽  
Massimo Giannozzi ◽  
Dieter R. Sporer ◽  
Filippo Cappuccini ◽  
...  
Keyword(s):  
Gas Turbines ◽  
Leakage Flow ◽  
Performance Gain ◽  
Tip Leakage Flow ◽  
Tip Leakage ◽  
Hot Gas ◽  
Industrial Gas Turbines ◽  
Basic Parameters ◽  
Component Shape ◽  
And Performance

An improvement in the energy efficiency of industrial gas turbines can be accomplished by developing abradable seals to reduce the stator/rotor gap to decrease the tip leakage flow of gases in the hot gas components of the turbine. “ABRANEW” is a project funded by the European Commission aimed at developing a high temperature abradable material capable of controlled abrasion and resistant to erosion and oxidation. In order to define the basic parameters such as the component shape, the existing gap, the expected gap reduction, the seal thickness and other geometric parameters, a comprehensive review of the design of the blade/shroud/casing system was performed.

Advanced Thermochemical Cleaning Procedures for Structural Braze Repair Techniques

2002 ◽  
Author(s):  
Alexander Stankowski
Keyword(s):  
High Temperature ◽  
Gas Turbines ◽  
Complete Removal ◽  
Salt Bath ◽  
Economic Benefits ◽  
Multiple Cracks ◽  
Deregulated Markets ◽  
Hot Gas ◽  
Processing Times ◽  
Industrial Gas Turbines

Hot gas path components of modern Industrial Gas Turbines (IGT) are exposed to extreme thermal, mechanical and chemical loading that ultimately leads to their deterioration. Modern GT designs provide for safe operation for a certain operation period. Higher firing temperatures and changing machine loads as a result of the deregulated markets call for highly sophisticated part designs and the use of cost-intensive superalloys. As the lifetime of critical parts is not infinite, they are reconditioned periodically or replaced to regain efficiency losses and to mitigate the risk of unscheduled outages due to hot gas path (HGP) failures. This paper presents advanced thermochemical preparation treatments that form the basis for the subsequent structural repairs, such as high temperature brazing. Before executing any repair step, coated components must be stripped of the consumed and degenerated coatings. Not all of the many techniques that are commonly used can guarantee reproducible and complete removal without damaging the substrate. Recently improved thermochemical techniques, such as a combination of advanced Chemical Stripping and Salt Bath Cleaning, enables the OEM to obtain clean components at low unit costs and for short processing times. In previous approaches, CrF2- and PTFE-based processes were used to clean surfaces and, principally, cracks from oxide scales before welding or brazing was carried out. These preparation techniques were indispensable for reworking superalloys, which cannot be cleaned sufficiently using conventional methods such as exposure under reducing atmospheres at high temperatures. Today, the high versatility of the “Dynamic Subatmospheric Fluoride Ion Cleaning” process (FIC) enables the OEM to run precisely tailored processes, allowing complete freedom to adjust the chemical activity of the gas phase and in so doing fulfil the specific conditions for any superalloy being reworked, even taking into account the varying grade of degradation sustained during service exposure. Weld repairs on superalloys are very sensitive to hot cracking, and high temperature brazing has established itself as a successful method for overcoming this problem. Furthermore, the intensively FIC cleaned surfaces can be regarded as the most important condition to enable a high quality bonding. Other key advantages of braze repairs are the uniform heat input that is possible, the high shape tolerance and the fact that multiple cracks can be simultaneously repaired. In addition, the brazing heat treatment allows controlled adjustment of the microstructural properties. Besides the economic benefits of the treatment, the brazed parts show excellent results in respect of their mechanical integrity. A schematic presentation of the repair sequence described in this paper is shown in the appendix (Fig. 17).

scholarly journals Influence of Rim Seal Geometry on Hot Gas Ingestion Into the Upstream Cavity of an Axial Turbine Stage

1999 ◽  
Author(s):  
Dieter Bohn ◽  
Bernd Rudzinski ◽  
Norbert Sürken ◽  
Wolfgang Gärtner
Keyword(s):  
Mach Number ◽  
Gas Turbines ◽  
Three Dimensional ◽  
Main Flow ◽  
Rotor Blades ◽  
Flow Rates ◽  
Hot Gas ◽  
Carbon Dioxide Gas ◽  
Industrial Gas Turbines ◽  
Rotor Disk

The ingestion of hot gas at the rim seal of a turbine has been investigated for a complete stage with nozzle guide vanes and rotor blades for two types of geometry: 1. the simple axial gap between a flat rotor disk and a flat stator disk, commonly used for industrial gas turbines and 2. an axial lip of the rim seal on the stator combined with a flat rotor disk, often found in aero engine applications. The clearance of the axial gap has been varied for the second type. The efficiency of the rim seal has been examined for different seal flow rates, rotational Reynolds numbers and Mach numbers in the main flow. For the determination of the sealing effectiveness carbon dioxide gas concentration measurements have been carried out in the wheelspace. The distribution of the static pressure in the vicinity of the seal and inside the wheelspace has been measured by means of pressure taps at the stator disk. It is shown that the external flow Mach number in the main flow has a significant effect on the sealing efficiency. As Mach number increases sealing efficiency goes down. The rotational Reynolds number has a distinct effect on the rim seal efficiency depending on the examined configuration. Even for high seal flow rates the ingestion of hot gas can not be fully avoided. The experimental results were the motivation for a three-dimensional CFD approach neglecting the influence of the rotor blades. The results give further insight into aerodynamic features of the ingestion phenomenon.

A222 Method for evaluating reliability of hot gas path parts of large industrial gas turbines

2015 ◽  
Vol 2015.20 (0) ◽  
pp. 191-194
Author(s):  
Yoichi SATO ◽  
Mayumi SAITO ◽  
Katsumi SUGIMOTO ◽  
Nobuyuki TAKENAKA
Keyword(s):  
Gas Turbines ◽  
Hot Gas ◽  
Industrial Gas Turbines

scholarly journals Tensile Behavior and Evolution of the Phases in the Al10Co25Cr8Fe15Ni36Ti6 Compositionally Complex/High Entropy Alloy

Entropy ◽  
2018 ◽  
Vol 20 (9) ◽  
pp. 646 ◽  
Author(s):  
Anna Manzoni ◽  
Sebastian Haas ◽  
Haneen Daoud ◽  
Uwe Glatzel ◽  
Christiane Förster ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Gas Turbines ◽  
Heat Treatments ◽  
Tensile Behavior ◽  
High Entropy Alloy ◽  
High Entropy Alloys ◽  
Dendritic Solidification ◽  
Cast State ◽  
High Entropy ◽  
Two Phases

Compositionally complex alloys, or high entropy alloys, are good candidates for applications at higher temperatures in gas turbines. After their introduction, the equiatomic Al17Co17Cr17Cu17Fe17Ni17 (at.%) served as a starting material and a long optimization road finally led to the recently optimized Al10Co25Cr8Fe15Ni36Ti6 (at.%) alloy, which shows promising mechanical properties. Investigations of the as-cast state and after different heat treatments focus on the evolution of the microstructure and provide an overview of some mechanical properties. The dendritic solidification provides two phases in the dendritic cores and two different ones in the interdendritic regions. Three of the four phases remain after heat treatments. Homogenization and subsequent annealing produce a γ-γ’ based microstructure, similar to Ni-based superalloys. The γ phase is Co-Cr-Fe rich and the γ’ phase is Al-Ni-Ti rich. The understanding of the mechanical behavior of the investigated alloy is supported and enhanced by the study of the different phases and their nanohardness measurements. The observations are compared with mechanical and microstructural data from commercial Ni-based superalloys, Co-based alloys, and Co-Ni-based alloys at the desired application temperature of ~800 °C.

High Temperature Brazing for Cobalt-Based Gas Turbine Components

2000 ◽  
Author(s):  
Wayne Greaves ◽  
Hans van Esch
Keyword(s):  
Mechanical Properties ◽  
High Temperature ◽  
Gas Turbine ◽  
Mechanical Testing ◽  
Gas Turbines ◽  
Cleaning Operation ◽  
Microstructural Evaluation ◽  
Industrial Gas Turbines ◽  
Crack Repair ◽  
The Common

A unique high temperature brazing process was developed for crack repair and surface restoration of cobalt superalloy components of industrial gas turbines. The repair method begins with a special cleaning operation consisting of both chemical and ultrahigh vacuum processes. A new high-temperature braze material, with a composition compatible with most of the common cobalt-based turbine alloys, was developed. The mechanical properties and weldability of the brazed material are comparable with those base alloys. Microstructural evaluation and mechanical testing confirmed the desired properties. Also, actual refurbishment applications of General Electric, Westinghouse, and ABB gas turbine components are shown.

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