Advanced Blading for Last Stages of Heavy Duty Gas Turbines: A Joint German Action

1992 ◽  
Author(s):  
U. Pickert ◽  
K. H. Keienburg ◽  
R. Bürgel ◽  
K. Schneider
Keyword(s):  
Gas Turbines ◽  
Turbine Blades ◽  
Current Status ◽  
Destructive Testing ◽  
Gas Turbine Blades ◽  
Material Component ◽  
Property Data ◽  
Static And Dynamic Loads ◽  
Component Property ◽  
Non Destructive

Large stationary gas turbine blades are highly stressed by static and dynamic loads. In 1986, ABB and Siemens/KWU initiated an R&D-program to develop large blades of Ni-base superalloys with higher operating capability. The aim of the program is to develop with main suppliers new manufacturing routes and non-destructive testing methods for measuring residual stresses as well as to generate with institutes the relevant material/component property data. So far — scheduled end of the program in mid 1993 — new manufacturing routes are established which allow a higher stressing of blades. The current status and future outlook will be highlighted.

scholarly journals Analysis of Feasibility to Assess Microstructure of Gas Turbine Blades by Means of the Thermographic Method

2010 ◽  
Vol 13 (1) ◽  
pp. 325-340 ◽  
Author(s):  
Artur Kułaszka ◽  
Józef Błachnio ◽  
Łukasz Kornas
Keyword(s):  
Gas Turbine ◽  
Turbine Blades ◽  
Turbine Engines ◽  
Destructive Testing ◽  
Initial Examination ◽  
Gas Turbine Blades ◽  
Non Invasive ◽  
Testing Technology ◽  
Non Destructive ◽  
Frequent Reason

Analysis of Feasibility to Assess Microstructure of Gas Turbine Blades by Means of the Thermographic MethodOperation of avionic turbine engines is always associated with possibility of various defects that may happen to turbine components, in particular to its blades. The most frequent reason for defects is overheating of the blade material but the thermal fatigue also occurs quite often. The most efficient examination method that provides plenty of information about structure of the investigated material of turbine blades is metallography but it is a destructive testing technology, so that the turbine no longer can be used after such investigation. This paper deals with methods of non-destructive tests that are currently in use and applicability of such methods to unbiased and trustworthy computer-aided diagnostics aimed to find out how the blade microstructure status varies in time. Results of initial examination of gas turbine blades are presented whereas the tests with use of the non-invasive thermographic method were carried out in order to assess condition of the blade material after the turbines had been subjected to the effect of high temperatures. Subsequently, the obtained results were successfully validated by means of the metallographic method. Eventually the conclusion could be made that the thermographic method makes it possible to achieve comprehensive and trustworthy information how microstructure of the blade materials is altered during the aircraft operation.

Advances in the Computed Tomography of Turbine Blades

2005 ◽  
Author(s):  
Martin Allen ◽  
Andrew T. Ramsey
Keyword(s):  
Computed Tomography ◽  
Data Extraction ◽  
Turbine Blades ◽  
Practical Method ◽  
International Standards ◽  
Non Destructive Testing ◽  
Destructive Testing ◽  
Wide Range ◽  
Non Destructive ◽  
Testing And Evaluation

Recent advances in virtually all areas of industrial Computed Tomography (CT) now allow faster, higher resolution, and increasingly economic CT inspection of turbine blades than ever before. CT is now used for a wide range of Non Destructive Testing and Evaluation (NDT&E) applications including first article inspection, defect detection, internal measurement, wear (and failure) analysis, and reverse engineering. Improvements range from the introduction of international standards on CT, through improvements in acquisition, reconstruction, and data extraction. Some of the most significant advances have been made in the ability to process the data generated by the CT systems. Today, CT is an increasingly practical method for the Non Destructive Testing and Evaluation of turbine blades.

Acoustic Thermography Testing of Industrial Gas Turbine Blades in the Service Stage

2008 ◽  
Author(s):  
Mattias Broddega˚rd ◽  
Christian Homma
Keyword(s):  
Gas Turbine ◽  
Test Object ◽  
Gas Turbines ◽  
Turbine Blades ◽  
Medium Size ◽  
Testing Time ◽  
Testing Technique ◽  
Ir Camera ◽  
Gas Turbine Blades ◽  
Industrial Gas Turbine

Gas turbine blades are operating under very demanding conditions. In modern industrial gas turbines, the rotating blades and the guide vanes of the first stages are hollow to allow internal cooling. This means that there is a possibility of having crack initiation on the internal surface of the components. Due to the complex casting geometry, this type of defects is very difficult to detect with conventional nondestructive testing techniques such as ultrasonic and radiographic testing. Siemens has developed a new non-destructive testing technique based on acoustic thermography, SIEMAT. The test object is energized by an ultrasonic excitation device. Due to the vibrations, a very slight heating will develop at cracks in the test object. The local increase of temperature is captured by a highly sensitive IR camera. The SIEMAT technique is capable of detecting both surface-breaking and internal cracks, including cracks under coatings. The testing time is very short, and the IR sequences are recorded for subsequent analysis. A major advantage for service applications is that the technique is mostly sensitive to closed defects such as cracks, since open defects where no contact between the faces is present, for example pores and scratch marks, will not cause any heat generation. Siemens is currently implementing the SIEMAT technique for assessment of service-exposed turbine blades from medium size gas turbines, which are due for reconditioning. By being able to verify that no internal cracks are present, the reliability of the reconditioned blades will be increased. This paper describes the SIEMAT testing technique, and the results obtained when applied on service-exposed industrial gas turbine blades.

scholarly journals Investigation of the Relationship between Degradation of the Coating of Gas Turbine Blades and Its Surface Color

Materials ◽  
2021 ◽  
Vol 14 (24) ◽  
pp. 7843
Author(s):  
Mariusz Bogdan ◽  
Józef Błachnio ◽  
Artur Kułaszka ◽  
Dariusz Zasada
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Protective Coatings ◽  
Turbine Blades ◽  
Operating Time ◽  
Surface Color ◽  
Metallographic Examination ◽  
Gas Turbine Blades ◽  
Study Results ◽  
The Relationship

This article presents issues concerning the relationship between the degradation of the coating of gas turbine blades and changes in the color of its surface. Conclusions were preceded by the determination of parameters characterizing changes in the technical condition of protective coatings made based on a metallographic examination that defined the morphological modifications of the microstructure of the coating, chemical composition of oxides, and roughness parameters. It has been shown that an increased operating time causes parameters that characterize the condition of the blades to deteriorate significantly. Results of material tests were compared with those of blade surface color analyses performed using a videoscope. Image data were represented in two color models, i.e., RGB and L*a*b* with significant differences being observed between parameters in both representations. The study results demonstrated a relationship between the coating degradation degree and changes in the color of the blade’s surface. Among others, this approach may be used as a tool to assess the condition of turbine blades as well as entire gas turbines.

Magnetic Particle Inspection of Turbine Blades in Power Generating Plants

1992 ◽  
Author(s):  
Clement Imbert ◽  
Krishna Rampersad
Keyword(s):  
Preventive Maintenance ◽  
Gas Turbines ◽  
Power Plants ◽  
Magnetic Particle ◽  
Martensitic Stainless Steel ◽  
Turbine Blades ◽  
Magnetic Particle Inspection ◽  
Optimum Placement ◽  
Non Destructive ◽  
Defect Detectability

Modern societies expect and depend on regular, relatively uninterrupted, supply of electric power. Preventive maintenance is therefore vital for power generating plants. Non-Destructive Evaluation (NDE) is a significant element of the maintenance programme of power plants. Power plants use a wide variety of steam and gas turbines. Turbine failure can occur without warning and with disastrous results. Such failures are invariably caused by cracks. Such defects are readily detected by NDE techniques such as Magnetic Particle Inspection (MPI) if they are on or near the surface and accessible. This paper reports on the use of MPI in the examination of martensitic stainless steel turbine blades in power plants in Trinidad and Tobago so as to quantify the testing parameters and determine field strength in relation to defect detectability. Specific recommendations are made regarding the configuration and optimum placement of magnetizing coils for turbine blade inspection insitu and detached.

Wide Gap Braze Repair of Gas Turbine Blades and Vanes—A Review

2011 ◽  
Vol 134 (1) ◽  
Author(s):  
Xiao Huang ◽  
Warren Miglietti
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Life Cycle Cost ◽  
Turbine Blades ◽  
Advanced Materials ◽  
Gas Turbine Blades ◽  
Rare Elements ◽  
Compositional Choices ◽  
Useful Life ◽  
Wide Gap

Gas turbine blades and vanes in modern gas turbines are subjected to an extremely hostile environment. As such, sophisticated airfoil designs and advanced materials have been developed to meet stringent demands and at the same time, ensure increased performance. Despite the evolution of long-life airfoils, damage still occurs during service thus limiting the useful life of these components. Effective repair of after-service components provides life-cycle cost reduction of engines, and as well, contributes to the preservation of rare elements heavily used in modern superalloys. Among these methods developed in the last four decades for the refurbishment and joining of superalloy components, wide gap brazing (WGB) technology has been increasingly used in the field owing to its ability to repair difficult to weld alloys, to build up substantially damaged areas in one operation, and to provide unlimited compositional choices to enhance the properties of the repaired region. In this paper, the historical development of wide gap repair technology currently used in industry is reviewed. The microstructures and mechanical properties of different WGB joints are compared and discussed. Subsequently, different WGB processes employed at major OEMs are summarized. To conclude this review, future developments in WGB repair of newer generations of superalloys are explored.

scholarly journals IMAGE OF THE SURFACE OF GAS TURBINE BLADE AS A DIAGNOSTIC SIGNAL

2013 ◽  
Vol 7 (4) ◽  
pp. 209-214
Author(s):  
Józef Błachnio ◽  
Iwona Zabrocka
Keyword(s):  
Gas Turbine ◽  
Turbine Blades ◽  
Statistical Parameter ◽  
Digital Processing ◽  
Pass Filter ◽  
Low Pass Filter ◽  
Gas Turbine Blades ◽  
The Status ◽  
Low Pass ◽  
Non Destructive

Abstract This paper outlines a non-destructive method that is suitable for evaluation of condition demonstrated by gas turbine blades and is based on digital processing of images acquired from the blade surface in visible light. To enable high clearness of these images the particular attention is paid to the problem of how to provide optimum conditions for investigations and mitigate geometrical distortions of images acquired from maintenance operations. The paper demonstrates that there are relationships between operation lifetime of blades and discoloration of their surfaces due to overheating of the blade material. These relationships are revealed by digital analysis of images acquired for the blade surfaces and expressed as statistical parameter of the first and second order. To improve unambiguity of the analysis results a low-pass filter was applied. It was demonstrated that these relationships are suitable for evaluation how much the status of the blade material microstructure is altered

scholarly journals CT Inspection of Cooled Turbine Blades

2020 ◽  
Vol 50 (3) ◽  
pp. 307-331
Author(s):  
Radosław Przysowa ◽  
Marek Chalimoniuk ◽  
Danuta Grzelka-Gajek ◽  
Ruslan Shakalo ◽  
Artem Karpenko
Keyword(s):  
Production Control ◽  
Turbine Blades ◽  
Gas Temperature ◽  
Inspection Method ◽  
Manufacturing Defects ◽  
X Ray ◽  
Gas Turbine Blades ◽  
Engine Efficiency ◽  
Operational Failures ◽  
Non Destructive

AbstractTo improve the engine efficiency by increasing the gas temperature, multi-layer cooling passages are applied in new designs of gas turbine blades. As a result, traditional non-destructive methods, which have been applied so far in the production control, became insufficient. The aim of this manuscript is to develop an inspection method for cooling passages of turbine blades, which would be helpful in detecting manufacturing defects of blades and their operational failures. GE v/tome/x/m 300 was applied to conduct dimensional control and check the interior of two types of turbine blades from turboshaft engines. The procedure for selecting X-ray parameters was suggested. The thickness of walls in the selected cross-section was measured with the accuracy of 0.01 mm, and the selected manufacturing defects of cooling passages were identified.

scholarly journals Assessment of Technical Condition Demonstrated by Gas Turbine Blades by Processing of Images for Their Surfaces / Oceny Stanu Łopatek Turbiny Gazowej Metodą Przetwarzania Obrazów Ich Powierzchni

2012 ◽  
Vol 21 (1) ◽  
pp. 41-50
Author(s):  
Józef Błachnio ◽  
Jarosław Spychała ◽  
Wojciech Pawlak ◽  
Artur Kułaszka
Keyword(s):  
High Temperature ◽  
Gas Turbine ◽  
Turbine Blades ◽  
Technical Condition ◽  
Test Method ◽  
Statistical Parameters ◽  
Gas Turbine Blades ◽  
First Order ◽  
Alloy Microstructure ◽  
Non Destructive

Abstract The paper presents a non-destructive test method that makes it possible to assess condition of gas turbine blades based on the analysis of their images acquired in visible light. The results of high temperature’s influence on the condition of blades are revealed. The direct relationship between the temperatures of blades and discoloration of their surfaces is demonstrated. These relationships have been found out by the analysis of images in the form of first order statistical parameters derived wherefrom. The studies revealed alterations of the blade superalloy microstructures entailed by the effect of high temperature, hence the results in the form of first order statistical parameters could be correlated against alterations of the blade superalloy microstructures. Eventually, the variations of first order statistical parameters as well as variations of the blade superalloy microstructures could be determined as the functions of temperature. These relationships make it possible to assess how much the alloy microstructure is altered due to high temperature merely by discoloration of the blade surface. The innovative method can be used for in-flight evaluation of the superalloy overheating for gas turbine blades in operation.

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