Creep Deformation and Microstructural Examination of a Prior Thermally Exposed Nickel Base Superalloy

Creep processes in MAR-M247 Nickel - Base Superalloy were studied at elevated temperatures. The stress exponents of creep rate n and time to fracture m indicate power-low (dislocation) creep regime and suggest the same controlling mechanism for the creep deformation and fracture. The variation of values of parameter n within the interval of applied stress may indicate changes in the rate-controlling creep deformation mechanism. The possibility of using of Monkman-Grant relationship for creep life prediction was demonstrated.

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Analysis of high-temperature creep deformation in a polycrystalline nickel-base superalloy

Materials Science and Engineering A ◽

10.1016/j.msea.2008.04.122 ◽

2009 ◽

Vol 510-511 ◽

pp. 301-306 ◽

Cited By ~ 22

Author(s):

A. Soula ◽

Y. Renollet ◽

D. Boivin ◽

J.-L. Pouchou ◽

D. Locq ◽

...

Keyword(s):

High Temperature ◽

Creep Deformation ◽

Nickel Base Superalloy ◽

High Temperature Creep ◽

Polycrystalline Nickel ◽

Temperature Creep ◽

Nickel Base ◽

Base Superalloy

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Creep deformation and crack growth behavior of a single-crystal nickel-base superalloy

Metallurgical and Materials Transactions A ◽

10.1007/bf02649750 ◽

1996 ◽

Vol 27 (4) ◽

pp. 829-837 ◽

Cited By ~ 14

Author(s):

S. J. Moss ◽

G. A. Webster ◽

E. Fleury

Keyword(s):

Single Crystal ◽

Crack Growth ◽

Creep Deformation ◽

Growth Behavior ◽

Crack Growth Behavior ◽

Nickel Base Superalloy ◽

Nickel Base ◽

Base Superalloy

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Strain and Damage-Based Analytical Methods to Determine the Kachanov–Rabotnov Tertiary Creep-Damage Constants

International Journal of Damage Mechanics ◽

10.1177/1056789511430519 ◽

2011 ◽

Vol 21 (8) ◽

pp. 1186-1201 ◽

Cited By ~ 8

Author(s):

Calvin M. Stewart ◽

Ali P. Gordon

Keyword(s):

Creep Behavior ◽

Creep Deformation ◽

Analytical Methods ◽

Numerical Optimization ◽

Creep Damage ◽

Tertiary Creep ◽

Nickel Base Superalloy ◽

Trial And Error ◽

Nickel Base ◽

Base Superalloy

In the power generation industry, the goal of increased gas turbine efficiency has led to increased operating temperatures and pressures necessitating nickel-base superalloy components. Under these conditions, the tertiary creep regime can become the dominant form of creep deformation. In response, the classical Kachanov–Rabotnov coupled creep-damage constitutive model is often used to predict the creep deformation and damage of Ni-base superalloys. In this model, the secondary creep behavior can be determined through analytical methods while the tertiary creep behavior is often found using trial and error or numerical optimization. Trial and error may produce no constants. Numerical optimization can be computationally expensive. In this study, a strain-based and damage-based approach to determine the tertiary creep behavior of nickel-base superalloys has been developed. Analytically determined constants are found for a given nickel-base superalloy. Creep deformation and damage evolution curves are compared. Methods to deal with stress dependence are introduced and studied.

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