Creep-life prediction of service-exposed turbine blades

In a previous study, high pressure turbine blades from an RB211-24C aero-derivative industrial gas turbine engine were sectioned and metallographically examined. The turbine blades were made of cast Mar-M002, a nickel-based superalloy. It was found that stress-assisted grain boundary oxidation (SAGBO) had occurred along the inner cooling channels near the leading edge at the turbine blade root, which accelerated crack formation and propagation through dynamic embrittlement. The cracks were characterized by the presence of large Hf, Al and O concentration. It appeared that the presence of oxygen in the inner cooling channels and the rapid oxidation of hafnium carbides aggravated the onset of failure through the action of SAGBO cracking. Following this examination, a creep life prediction analysis of the RB211-24C first stage blades was performed at Life Prediction Technologies Inc. (LPTi). According to the results from LPTi’s creep life prediction, the leading edge region near the blade root is most vulnerable to combined creep and oxidation damage accumulation due to high strain accumulation, as a result of high temperatures, stress, and limited inspection ability of the inner channels. In the present study, the LPTi prediction results are compared with the metallographic analysis of RB211-24C blades. It is confirmed that SAGBO in combination with creep leads to cracking in the predicted region and the worst case creep analysis results match favorably with the field experience.

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Creep Life Prediction of Ni-Base Superalloy Used in Advanced Gas Turbine Blades by Electrochemical Method.

JSME International Journal Series A ◽

10.1299/jsmea.43.156 ◽

2000 ◽

Vol 43 (2) ◽

pp. 156-165 ◽

Cited By ~ 3

Author(s):

Shin-ichi Komazaki ◽

Tetsuo Shoji ◽

Minoru Sato

Keyword(s):

Gas Turbine ◽

Electrochemical Method ◽

Life Prediction ◽

Turbine Blades ◽

Creep Life ◽

Gas Turbine Blades ◽

Creep Life Prediction ◽

Base Superalloy

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ICME Framework for Damage Assessment and Remaining Creep Life Prediction of In-Service Turbine Blades Manufactured with Ni-Based Superalloys

Integrating Materials and Manufacturing Innovation ◽

10.1007/s40192-019-00161-4 ◽

2019 ◽

Vol 8 (4) ◽

pp. 509-520

Author(s):

Chao Fu ◽

Yadong Chen ◽

Siliang He ◽

Stoichko Antonov ◽

Longfei Li ◽

...

Keyword(s):

Damage Assessment ◽

Life Prediction ◽

Turbine Blades ◽

Creep Life ◽

Creep Life Prediction

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Creep Life Prediction of Aircraft Turbine Disc Alloy Using Continuum Damage Mechanics

International Journal of Turbo and Jet Engines ◽

10.1515/tjj-2017-0043 ◽

2017 ◽

Vol 38 (1) ◽

pp. 25-30

Author(s):

Yan-Feng Li ◽

Zhisheng Zhang ◽

Chenglin Zhang ◽

Jie Zhou ◽

Hong-Zhong Huang

Keyword(s):

Numerical Analysis ◽

Test Data ◽

Life Prediction ◽

Damage Mechanics ◽

Continuum Damage Mechanics ◽

Creep Model ◽

Continuum Damage ◽

Creep Life ◽

Creep Life Prediction ◽

Turbine Disc

Abstract This paper deals with the creep characteristics of the aircraft turbine disc material of nickel-base superalloy GH4169 under high temperature. From the perspective of continuum damage mechanics, a new creep life prediction model is proposed to predict the creep life of metallic materials under both uniaxial and multiaxial stress states. The creep test data of GH4169 under different loading conditions are used to demonstrate the proposed model. Moreover, from the perspective of numerical simulation, the test data with analysis results obtained by using the finite element analysis based on Graham creep model is carried out for comparison. The results show that numerical analysis results are in good agreement with experimental data. By incorporating the numerical analysis and continuum damage mechanics, it provides an effective way to accurately describe the creep damage process of GH4169.

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