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.

Heat resistance of gas turbine blades with protective coatings

1986 ◽  
Vol 18 (5) ◽  
pp. 610-615 ◽  
Author(s):  
A. P. Voloshchenko ◽  
G. N. Tret'yachenko ◽  
L. B. Getsov ◽  
B. M. Zinchenko ◽  
I. S. Malashenko ◽  
...  
Keyword(s):  
Heat Resistance ◽  
Gas Turbine ◽  
Protective Coatings ◽  
Turbine Blades ◽  
Gas Turbine Blades

An X-ray study of residual macrostresses in protective coatings for gas-turbine blades

1997 ◽  
Vol 39 (11) ◽  
pp. 484-488
Author(s):  
Yu. D. Yagodkin ◽  
K. M. Pastukhov ◽  
E. V. Milyaeva ◽  
S. A. Muboyadzhyan ◽  
S. A. Budinovskii
Keyword(s):  
Gas Turbine ◽  
Protective Coatings ◽  
Turbine Blades ◽  
X Ray ◽  
Gas Turbine Blades ◽  
Residual Macrostresses

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.

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.

Rainbow Field Test of Coatings for Hot Corrosion Protection of Gas Turbine Hot Section Components: II — Vane Coatings

1989 ◽  
Author(s):  
Mark Van Roode
Keyword(s):  
Gas Turbine ◽  
Field Test ◽  
Coating Thickness ◽  
Hot Corrosion ◽  
Liquid Fuel ◽  
Turbine Blades ◽  
Lower Grade ◽  
Metallographic Examination ◽  
Gas Turbine Blades ◽  
Thickness Measurements

A rainbow field test sponsored by the Electric Power Research Institute (EPRI) under contract RP 2465-1 was performed to evaluate the comparative hot corrosion resistance of commercially available coatings for gas turbine blades and vanes. A 10,307-hr field test was carried out on a Solar Centaur T-4000 gas turbine operating on a lower grade liquid fuel at the Owens-Illinois, Inc. glass manufacturing facility in Valera, Venezuela. This paper reviews the results of an evaluation of the performance of a simple aluminide, a Pt, Rh-aluminide and two MCrAlY (M = Co, NiCo) overlays applied to the first stage FSX-414 vanes. As found for blade coatings, on the basis of visual and metallographic examination, and remnant coating thickness measurements, it was established that the MCrAlY coatings were generally more effective than the simple aluminide and the Pt, Rh-aluminide in providing protection to first stage vanes. A remnant coating thickness index (RCTT) was used to express coating survival and protectiveness quantitatively. The results of the study have been compared with literature.

scholarly journals Computer Predictions of Erosion Damage in Gas Turbines

1987 ◽  
Author(s):  
A. F. Abdel Azim El-Sayed ◽  
A. Brown
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Iterative Procedure ◽  
Pressure Coefficient ◽  
Turbine Blades ◽  
Engine Performance ◽  
Erosion Damage ◽  
Gas Turbine Blades ◽  
Coefficient Distribution ◽  
Blade Section

In this article an iterative procedure is presented for estimating erosion in axial gas turbine blades. The procedure is applied to a two stage turbine and the erosion is estimated for a 12,000 hour engine running time. The effect of the erosion on engine performance is estimated through changes in pressure coefficient distribution around a blade section.

Industrial technology of deposition of two-layer plasma heat-protective coatings on gas turbine blades

2020 ◽  
Vol 2020 (4) ◽  
pp. 28-31
Author(s):  
V.A. Akrimov ◽  
◽  
I.M. Grechanyuk ◽  
Yu.O. Smashnyuk ◽  
V.G. Grechanyuk ◽  
...  
Keyword(s):  
Gas Turbine ◽  
Protective Coatings ◽  
Turbine Blades ◽  
Industrial Technology ◽  
Gas Turbine Blades
Sign in / Sign up

Export Citation Format

Share Document