Metallurgical Assessment of Degradation of a Gas Turbine Bucket Made of Inconel 738LC Alloy After 24000 H in Service

2004 ◽  
Author(s):  
Zdzislaw Mazur ◽  
Alberto Luna-Rami´rez ◽  
Julio A. Jua´rez-Islas
Keyword(s):  
Gas Turbine ◽  
Base Alloy ◽  
Nickel Base Alloy ◽  
Gamma Prime ◽  
Size Characterization ◽  
Nickel Base ◽  
Degradation Degree ◽  
Inconel 738Lc ◽  
Turbine Bucket ◽  
Blade Coating

The assessment of service induced degradation of nickel-base alloy Inconel 738LC of the gas turbine blade airfoil hot section, after 24000 hours of operation at high temperature is presented. The assessment include the blade coating degradation, changes of the gamma prime (γ′) phase (aging and coarsening), carbides and brittle phases precipitation, grain type and size characterization, and evaluation of interface coating/base alloy and cracks. The results of blade hot section (airfoil) microstructural assessment are compared to the cold reference zone (bucket root) to show the degradation degree of the alloy and its lifetime consumed. Finally, conclusions are presented indicating the alloy main microstructure elements which influence of blade behavior and the factors that can be used to determine the grade of material deterioration and lifetime consumed.

CM-R 411

Alloy Digest ◽  
1967 ◽  
Vol 16 (9) ◽  
Keyword(s):  
Shear Strength ◽  
High Temperature ◽  
Gas Turbine ◽  
Precipitation Hardening ◽  
Base Alloy ◽  
Heat Treating ◽  
Nickel Base Alloy ◽  
Jet Engine ◽  
Temperature Performance ◽  
Nickel Base

Abstract CM-R41 is a vacuum-melted, precipitation hardening nickel-base alloy possessing outstanding properties in the temperature range of 1200 F to 1800 F. It is recommended for jet engine and gas turbine components operating at high temperatures. This datasheet provides information on composition, physical properties, elasticity, tensile properties, and shear strength as well as creep. It also includes information on high temperature performance as well as forming, heat treating, machining, and joining. Filing Code: Ni-127. Producer or source: Cannon-Muskegon Corporation.

CARPENTER M-252

Alloy Digest ◽  
1973 ◽  
Vol 22 (9) ◽  
Keyword(s):  
Corrosion Resistance ◽  
High Temperature ◽  
Physical Properties ◽  
Gas Turbine ◽  
Base Alloy ◽  
Heat Treating ◽  
Nickel Base Alloy ◽  
Jet Engine ◽  
Temperature Performance ◽  
Nickel Base

Abstract CARPENTER M-252 is an age-hardenable nickel-base alloy designed for highly stressed parts operating at temperatures up to 1600 F. Its prime application is for jet-engine and gas-turbine buckets. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties as well as creep. It also includes information on high temperature performance and corrosion resistance as well as forming, heat treating, machining, and joining. Filing Code: Ni-195. Producer or source: Carpenter.

Embrittlement of Precipitation Hardenable Nickel-Base Alloys by Oxygen

1971 ◽  
Vol 93 (2) ◽  
pp. 225-230 ◽  
Author(s):  
M. Prager ◽  
G. Sines
Keyword(s):  
Grain Size ◽  
Surface Energy ◽  
Base Alloy ◽  
Tensile Tests ◽  
Inert Atmosphere ◽  
Nickel Base Alloy ◽  
Gamma Prime ◽  
Tensile Fractures ◽  
Nickel Base ◽  
Short Time

A study was made of the embrittling effects of oxygen on Rene´ 41, a nickel-base alloy hardened by precipitation of gamma prime. In short time tensile tests in air it was found that from 750 to 900 deg C oxygen promoted initiation and rapid propagation of intergranular cracks, while in the absence of oxygen, tensile fractures were transgranular and ductility was much improved. Sensitivity to embrittlement by oxygen decreases with coarsening of gamma prime. When gamma prime is hyperfine, probably less than 100 Å, embrittlement is greatest and follows the predictions of a Petch-Stroh model for the initiation of cracks ahead of pile-ups of dislocations. In accordance with the model, the ductility of Rene´ 41 increased in proportion of the reciprocal of the square roo of grain size. Calculated on the basis of the model, the surface energy of Rene´ 41 in air was 400 ergs/cm2, considerably lower than would be expected for an alloy of nickel in an inert atmosphere.

ALLVAC 718-OP

Alloy Digest ◽  
2003 ◽  
Vol 52 (3) ◽  
Keyword(s):  
Corrosion Resistance ◽  
High Temperature ◽  
Physical Properties ◽  
Base Alloy ◽  
Melting Process ◽  
Heat Treating ◽  
Nickel Base Alloy ◽  
Gamma Prime ◽  
Temperature Performance ◽  
Nickel Base

Abstract Allvac 718-OP is a versatile alloy that is vacuum induction melted followed by a consumable melting process. The alloy is a special chemistry vacuum melted version of standard Allvac 718. It is a precipitation-hardenable, nickel-base alloy that can be used from -253 deg C (-423 deg F) to 704 deg C (1300 deg F). The main hardening constituent is a niobium-containing gamma prime precipitate. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties. It also includes information on low and high temperature performance, and corrosion resistance as well as forming, heat treating, machining, and joining. Filing Code: Ni-605. Producer or source: Allvac Metals Company.

FIRTH FS-718

Alloy Digest ◽  
1966 ◽  
Vol 15 (3) ◽  
Keyword(s):  
Corrosion Resistance ◽  
High Temperature ◽  
Physical Properties ◽  
Surface Treatment ◽  
Gas Turbine ◽  
Base Alloy ◽  
Heat Treating ◽  
Nickel Base Alloy ◽  
Temperature Performance ◽  
Nickel Base

Abstract FIRTH FS-718 is an austenitic nickel-base alloy having good cryogenic properties, and excellent strength and oxidation resistance up to 1300 F. It is highly recommended for missile and gas turbine components. This datasheet provides information on composition, physical properties, elasticity, and tensile properties as well as creep. It also includes information on low and high temperature performance, and corrosion resistance as well as forming, heat treating, machining, joining, and surface treatment. Filing Code: Ni-112. Producer or source: Firth Sterling Inc..

UDIMET 901

Alloy Digest ◽  
1970 ◽  
Vol 19 (7) ◽  
Keyword(s):  
High Temperature ◽  
Physical Properties ◽  
Tensile Properties ◽  
Gas Turbine ◽  
Rupture Strength ◽  
Base Alloy ◽  
Heat Treating ◽  
Nickel Base Alloy ◽  
Temperature Performance ◽  
Nickel Base

Abstract Udimet 901 is a nickel-base alloy having high tensile and rupture strength to 1200 F. It is recommended for use in aircraft, aerospace and gas turbine components. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties as well as creep. It also includes information on high temperature performance as well as forming, heat treating, machining, and joining. Filing Code: Ni-155. Producer or source: Special Metals Corporation. See also Alloy Digest Ni-111, February 1966.

CARPENTER WASPALOY

Alloy Digest ◽  
1986 ◽  
Vol 35 (2) ◽  
Keyword(s):  
Corrosion Resistance ◽  
Gas Turbine ◽  
Precipitation Hardening ◽  
Elevated Temperatures ◽  
Base Alloy ◽  
Heat Treating ◽  
Vacuum Arc ◽  
Nickel Base Alloy ◽  
Turbine Engine ◽  
Nickel Base

Abstract CARPENTER WASPALOY is a precipitation-hardening nickel-base alloy designed for use at elevated temperatures. It is used for gas turbine engine parts requiring considerable strength and corrosion resistance up to 1600 F. The alloy is usually vacuum-induction melted or vacuum induction plus vacuum-arc remelted. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties as well as creep. It also includes information on corrosion resistance as well as forming, heat treating, machining, and joining. Filing Code: Ni-328. Producer or source: Carpenter.

INCOLOY 901

Alloy Digest ◽  
1957 ◽  
Vol 6 (12) ◽  
Keyword(s):  
High Temperature ◽  
Gas Turbine ◽  
Rupture Strength ◽  
Base Alloy ◽  
Heat Treating ◽  
Nickel Base Alloy ◽  
International Nickel Company ◽  
Temperature Performance ◽  
Nickel Base ◽  
Industrial Gas Turbine

Abstract INCOLOY 901 is a nickel-base alloy having creep and rupture strength at 1000 to 1400 F. It is recommended for use in aircraft and industrial gas turbine components. This datasheet provides information on composition, physical properties, elasticity, and tensile properties as well as creep. It also includes information on high temperature performance as well as forming, heat treating, machining, and joining. Filing Code: Ni-38. Producer or source: The International Nickel Company Inc..

The Nature of Delta Phase Precipitation in Inconel 718

1982 ◽  
Vol 40 ◽  
pp. 724-725
Author(s):  
L. S. Lin ◽  
C. C. Law
Keyword(s):  
Inconel 718 ◽  
Base Alloy ◽  
High Strength ◽  
Physical Metallurgy ◽  
Nickel Base Alloy ◽  
Phase Precipitation ◽  
Weight Percentage ◽  
Delta Phase ◽  
The Subject ◽  
Nickel Base

Inconel 718, a precipitation hardenable nickel-base alloy, is a versatile high strength, weldable wrought alloy that is used in the gas turbine industry for components operated at temperatures up to about 1300°F. The nominal chemical composition is 0.6A1-0.9Ti-19.OCr-18.0Fe-3Mo-5.2(Cb + Ta)- 0.1C with the balance Ni (in weight percentage). The physical metallurgy of IN 718 has been the subject of a number of investigations and it is now established that hardening is due, primarily, to the formation of metastable, disc-shaped γ" an ordered body-centered tetragonal structure (DO2 2 type superlattice).

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