• Title/Summary/Keyword: INCONEL

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A Study on Fretting-Wear Behavior of Inconel 690 due to Surrounding Temperature (주위 온도에 따른 Inconel690의 마멸 거동에 관한 연구)

  • 임민규;박동신;김대정;이영제
    • Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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    • 2001.11a
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    • pp.296-303
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    • 2001

  • In nuclear power steam generators, high flow rates can induce vibration of the tubes resulting in fretting wear damage due to contacts between the tubes and their supports. In this paper the fretting wear tests and the sliding wear tests were performed using the steam generator tube materials of Inconel 690 against STS 304. Sliding tests with the pin-on-disk type tribometer were done under various applied loads and sliding speeds at air and water environment. Fretting tests were done under various vibrating amplitudes, applied normal loads and various temperatures. From the results of sliding and fretting wear tests, the wear of Inconel 690 can be predictable using the work rate model. Depending on normal loads and vibrating amplitudes, distinctively different wear mechanisms and often drastically different wear rates can occur. At room temperature, the wear coefficient K of Inconel 690 is 7.57${\times}$10$\^$13/Pa$\^$1/ in air and it is 1.93${\times}$10$\^$13/Pa$\^$1/ in water. At room temperature, it is found that the wear volume in air is more than in water. In water, the wear coefficient K at 50$^{\circ}C$ and 80$^{\circ}C$ is 4.35${\times}$10$\^$-13/Pa$^1$ and 5.81${\times}$10$\^$-13/Pa$^1$ respectively, Therefore, it is found that the wear volume extremely increases by increasing on temperature in water. This study shows that the dissolved oxygen with temperature increment increases and the wear due to fluidity is severe.

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Analysis of Microstructural Refinement for Inconel 706 during Hot Forging Process through Reheating and Strain (Inconel 706의 열간단조 공정 중 재가열과 변형양에 따른 결정립 미세화에 대한 분석)

  • S. G. Seong;H. J. Kang;Y. S. Lee;S. Y. Lee;U. J. Lee;H. I. Jae;J. H. Shin;E. Y. Yoon
    • Transactions of Materials Processing
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    • v.32 no.5
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    • pp.239-246
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    • 2023

  • To reduce the forming load due to the temperature drop, during the hot forging process, a reheating hot forging process design is required that to repeat heating and forging. However, if the critical strain required for recrystallization is not induced during forging and grain growth becomes dominant due to the reduction in dislocation density due to repeated heating, the mechanical properties may deteriorate. Therefore, in this study, Inconel 706 alloy was applied, and the grain refinement behavior was comparatively analyzed according to the number of reheating times and effective strain during reheating hot forging process. Reheating was carried out with a total compression rate of 40% up to 4 times. The Inconel 706 compression test specimens heated once showed finer grains as the effective strain increased due to the dynamic recrystallization phenomenon. However, as the number of heating increases, grain refinement was observed even in a low effective strain distribution of 0.43 due to static recrystallization during reheating. Moreover, grain growth occurs at a relatively low effective strain of 0.43 when the number of reheating is four or more. Therefore, it was effective to apply an effective strain of 0.43 or more during hot forging to Inconel 706 in order to induce crystallization through grain refinement and improve the properties of forged products. In addition, we could notice that up to three reheating times condition was appropriate to prevent grain growth and maintain fine grain size.

  • https://doi.org/10.5228/KSTP.2023.32.5.239 인용 PDF HTML

NDT of a Nickel Coated Inconel Specimen Using by the Complex Induced Current - Magnetic Flux Leakage Method and Linearly Integrated Hall Sensor Array (복합 유도전류-누설자속법과 고밀도 홀센서배열에 의한 니켈 코팅 인코넬 시험편의 비파괴검사)

  • Jun, Jong-Woo;Lee, Jin-Yi;Park, Duk-Keun
    • Journal of the Korean Society for Nondestructive Testing
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    • v.27 no.5
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    • pp.375-382
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    • 2007

  • Nondestructive testing (NDT) by using the electromagnetic methods are useful for detecting cracks on the surface and subsurface of the metal. However, when the material contains both ferromagnetic and paramagnetic materials, it is difficult for NDT to detect and analyze cracks using this method. In addition the existence of a partial ferromagnetic material can be incorrectly characterized as a crack in the several cases. On the other hand a large crack has sometimes been misunderstood as a partially magnetized region. Inconel 600 is an important material in atomic energy plant. A nickel film is coated when a crack a appears on an Inconel substrate. Cracks are difficult to detect on the combined material of an Inconel substrate with a nickel film, which are paramagnetic and ferromagnetic material respectively. In this paper, a scan type magnetic camera, which uses a complex induced current-magnetic flux leakage (CIC-MFL) method as a magnetic source and a linearly integrated Hall sensor array (LIHaS) on a wafer as the magnetic sensors, was examined for its ability to detect cracks on the combined material. The evaluation probability of a crack is discussed. In addition the detection probability of the minimum depth was reported.

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