• Title/Summary/Keyword: Turbine Disc

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A Study on the Prediction of Grain Size Distribution in Hot Forging of Waspaloy Turbine Disc (Waspaloy 터빈디스크의 열간 단조시 결정립분포 해석에 관한 연구)

  • Yeom, Jong-Taek;Lee, Chong-Soo;Kim, Jeoung-Han;Lee, Dong-Geun;Park, Nho-Kwang
    • Journal of the Korea Institute of Military Science and Technology
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    • v.9 no.2
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    • pp.70-76
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    • 2006
  • The microstructure evolution during a hot forging of Waspaloy was investigated using the recrystallization model and FEM simulation. In order to obtain an uniform microstructure, hot forging was carried out by two step. The change of grain size during hot forging has a deep connection with dynamic recrystallization behavior. Avrami-type constitutive equation for the dynamic recrystallization was implemented into an user subroutine of 2D FE simulator. The evolution of grain structure in the two-step forging of Waspaloy was simulated using the 2D FEM user-subroutine. The detailed variation of microstructures due to dynamic recrystallization could effectively be predicted at various locations in a forged pancake.

Direct Differentiation Method for Shape Design Sensitivity Analysis of Axisymmetric Elastic Solids by the BEM and Shape Optimization of Turbin Disc (경계요소법에 의한 축대칭 탄성체의 형상설계 민감도해석을 위한 직접미분법과 터빈 디스크의 형상최적설계)

  • Lee, Bu-Yun
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.20 no.5
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    • pp.1458-1467
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    • 1996
  • A direct differentiationmethod is presented for the shape design sensitivity analysis of axisymmeetric elastic solids. Based on the exisymmetric boundary integralequaiton formulation, a new boundary ntegral equatio for sensitivity analysis is derived by taking meterial derivative to the same integral identity that was used in the adjoint variable melthod. Numerical implementation is performed to show the applicaiton of the theoretical formulation. For a simple example with analytic solution, the sensitivities by present method are compared with analytic sensitivities. As an application to the shape optimization, an optimal shape of a gas turbine disc toinimize the weight under stress constraints is found by incorporating the sensitivity analysis algorithm in an optimizatio program.

A Study on the Flaw Evaluation in the Straddle Mount Type Low Pressure Turbine Disc Using Phased Array Ultrasonic Technique (위상 배열 초음파 기법을 이용한 Straddle Mount형 저압 터빈 디스크 결함 평가에 관한 연구)

  • Yang, Seung-Han;Yoon, Byung-Sik;Kim, Yong-Sik
    • Journal of the Korean Society for Nondestructive Testing
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    • v.26 no.4
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    • pp.231-238
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    • 2006
  • Nondestructive examination for low pressure turbine disc in standard nuclear power plant using phased array technique was studied. For this purpose, disc mockups were made and notches were machined in the mockups. Detection and length sizing by different methods are compared. Depth of deep notches could be measured by using AATT(absolute arrival time technique) or RATT(relative arrival time technique) but shallow notches that must be detected in early stage couldn't be measured by these two methods. For this case, notch depth was estimated by using signal response angle range and preyed usefulness.

An Overview of The Commercialisation of The Spray Forming Process

  • Leatham, Alan
    • Journal of Korean Powder Metallurgy Institute
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    • v.3 no.4
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    • pp.227-232
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    • 1996
  • (i) The development of a metallurgical bond during the spray forming of clad products has offered the possibility of manufacturing large rolls, including those used in hot and cold strip mills. Small rolls are already being produced in Japan. (ii) Technical developments, including the use-of-multi-atomizers have resulted in the elimination of porosity from the internal bore of a sprayed tube. Bimetallic tubing can also be manufactured and the installation of a 4.5 ton tube plant in the USA should provide low operation costs. (iii) Spray forming offers a potentially low cost manufacturing route for superalloy ring/casing components in high strength superalloys. (iv) A large pilot plant has been built for the spray forming of ultra-clean superalloys for turbine disc applications. (v) Using twin-atomizing technology, special steel billets have been spray formed up to 400mm diameter with deposition yields in excess of 90%. (vi) Al/Si alloy extrusion billets with excellent dimensional tolerances are being manufactured for large scale automotive applications. Several new aluminum alloys have also been developed, including high strength, low density and low cocfficient of expansion materials. (vii) New copper alloys have been developed and pilot plants are in operation to produce these alloys once markets have become established.

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Parametric Study of Gas Turbine Engine Disc using Axisymmetry and Sector Analysis Model (축대칭 및 섹터 해석 모델을 활용한 가스터빈 엔진 디스크의 형상 변수 고찰)

  • Huh, Jae Sung
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.37 no.6
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    • pp.769-774
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    • 2013
  • Turbine blades and disc, which are one of the most important rotating parts of a gas turbine engine, are required to have highly efficient performance in order to minimize the total life cycle costs. Owing to these requirements, these components are exposed to severe conditions such as extreme turbine inlet temperatures, high compression ratios, and high speeds. To evaluate the structural integrity of a turbine disc under these conditions, material modeling and finite element analysis techniques are essential; furthermore, shape optimization is necessary for determining the optimal solution. This study aims to generate 2D finite element models of an axisymmetry model and a sector one and to perform thermal-structural coupled-field analysis and contact analysis. Structurally vulnerable areas such as the disc bore and disc-blade interface region are analyzed by a parametric study. Finally, an improved design is provided based on the results, and the necessity of elaborate shape optimization is confirmed.

Evaluation of Fatigue Crack Propagation Behavior of Nickel-based Powder Metallurgy Superalloy for Aircraft at Elevated Temperature (항공기 터빈 디스크용 니켈기 초내열 분말야금 합금의 고온 피로균열진전 거동 비교 평가)

  • Yoon, Dong Hyun;Na, Seong Hyeon;Kim, Jae Hoon;Kim, Hongkyu;Kim, Donghoon
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.41 no.8
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    • pp.751-758
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    • 2017
  • The behavior of fatigue crack growth of nickel-based powder metallurgy superalloy that could be used in aircraft turbine disc is investigated at room temperature, and $650^{\circ}C$ considering real operating conditions. The direct current potential drop(DCPD) method was used to measure the crack length of material in real time according to ASTM E647. Tests were performed with various stress ratios (0.1 and 0.5). Experimental results show that stress ratio, and temperature all affect the behavior of fatigue crack growth. As the stress ratio and temperature increase, the fatigue crack growth rate of nickel-based powder metallurgy superalloy also increases. Results were compared and reviewed with fatigue crack growth rates of other nickel-based superalloy materials (Inconel-100) that were studied in previous papers. Fractography analysis of the fractured specimens was performed using as SEM.