• Proceedings of the Korean Nuclear Society Conference
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• 1997.05b
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• pp.118-122
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• 1997

차세대 원자력발전소 증기발생기 전열관 재료로 채택된 니켈기저합금으로 기존 전열관 재료인 인코넬600에 비해 고온 고압 조건에서 응력부식균열에 강한 장점을 가진 합금인 인코넬690 시료에 최대 에너지 120 keV의 질소 이온빔을 조사하여 이 재료의 기계적 특성 변화를 관측하였다. 특성 시험으로는 표면 경화를 관찰하기 위한 미세 경도 시험을 수행하여 미세 경도 증가를 확인하였다 아울러 표면 경화가 피로 특성에 미치는 영향을 관찰하기 위해 피로 균열 전파 시험을 수행하여 이온 주입으로 인한 표면 경화가 피로 균열 전파를 촉진시킴을 관찰하였다.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.35 no.8
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• pp.951-956
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• 2011

Inconel alloys are generally used as steam generator tubes in nuclear power plants. These alloys are highnickel chromium alloys that exhibit excellent resistance to aqueous corrosion. In this paper, the effects of elevated temperatures such as an operating temperature of $320^{\circ}C$ on the fretting fatigue behavior of inconel 600 and 690. We observed that the plain and fretting fatigue limits at $320^{\circ}C$ were slightly lower than those at room temperature. The frictional forces varied depending on the number of load cycles. After each test, we studied the fretting fatigue mechanisms via SEM observations. These results can be used for structural integrity evaluations at elevated temperatures and for studying fretting damage in steam generator systems.

• Proceedings of the Korean Nuclear Society Conference
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• 1995.10a
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• pp.437-443
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• 1995

국내, 외에서 원자력발전소의 주요 구성 기기인 증기발생기의 세관 건전성과 관련 설계개선을 위한 연구가 활발히 진행되고 있다[2,3,4,5,6]. 현재 가동중인 발전소에서는 개선된 증기발생기로 교체하고자 하는 검토가 이루어지고 있으며, 설계중인 발전소에서는 중기발생기의 건전성을 향상시키기 위한 노력이 진행되고 있다. 본 논문에서 기존에 조사되고 검토된 자료를 바탕으로 [2] 현재까지 주로 사용되어온 증기발생기의 세관 재질을 인코넬 600 MA(mill annealed)로 사용할 때 40년 수명동안 증기발생기의 건전성을 보장할 수 있는 고온관의 온도를 분석한 결과 적절한 온도가 607$^{\circ}$F(319.4$^{\circ}C$)임을 알았다. 그리고 이 온도를 반영할 때 계통설계에 영향을 주는 설계사항에 대하여 검토하였고, 추가로 인코넬 600 MA보다 고온조건에서 건전성이 양호한 인코넬 690 TT(thermal treatment)를 사용할 때 설계에 미치는 영향도 검토하였다. 이러한 분석결과는 추후 국내 원자력발전소에서 보다 증기발생기의 건전성을 보장하기 위해 설계개선을 하고자 할 때 기초 자료가 되리라 판단한다.

• Proceedings of the KSME Conference
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• 2005.11a
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• pp.110.2-110.2
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• 2005

• Proceedings of the Korean Nuclear Society Conference
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• 1997.05b
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• pp.104-109
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• 1997

인코넬600 합금을 열처리상태 및 변형속도등이 서로 다른 응력부식균열(SCC) 발생 조건하에서 정변형속도 시험법으로 인장시켜 그때 발생되는 AE신호와 부식전류를 측정하여 균열거동과 비교하므로서 SCC 발생 및 진전을 AE로서 적절히 탐지할 수 있는가를 연구하였다. 그 결과 SCC. 연성파괴 및 기계적인 변형에서 발생되는 AE는 amplitude 준위에 의해 식별가능하며, 이것은 AE amplitude 준위가 AE발생원을 식별할 수 있는 중요한 변수가 될 수 있음을 의미한다. 또한 AE 발생시점과 전기 화학적 전류변동이 들 일치하는 것으로 나타나 입계응력부식 균열 진전이 AE에 의해 적절히 탐지될 수 있음을 알 수 있다.

• Proceedings of the KWS Conference
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• 1998.10a
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• pp.288-291
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• 1998

Inconel 600 alloy is used as the material of nuclear steam generator tubing because of its mechanical properties, formability, and corrosion properties. According to reports, the life time of nuclear power plants decreases because of the pitting, intergranular attack, primary water stress corrosion cracking(PWSCC), and intergranular stress corrosion cracking(IGSCC), and denting in the steam generator. The SCC test is very important because of SCC appears in various environment such as solutions, materials, and stress. The C-Rig specimen was made of the steam generator welded sleeve repairing by the pulsed Nd:YAG laser. In the corrosion invironment, corrosion solutions are Primary Water, Caustic, and Sulfate solution and corrosion time is 1624-4877hr. The permitted stress is 30-60ksi.In this C-Ring SCC test is the relationship between corrosion depth, crack and corrosion environment is evaluated. SCC was happens in Sulfate and Corrosion solution but doesn't happen in Primary Water. The corrosion time and stress is very affected by the severely environment of Sulfate or Caustic solution. The microstructure observation indicates that SCC causes interganular failure in the grain boundary of vertical direction.

• Analytical Science and Technology
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• v.17 no.5
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• pp.416-422
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• 2004

Time-resolved laser induced breakdown spectroscopy (TRELIBS) has been developed and applied to the qualitative analysis of the component materials of nuclear power plant. The alloy samples used in this work were carbon steels (A106 Gr. B; A336 P11; A335 P22), stainless steels (type 304; type 316) and inconel alloys (Inconel 600; Inconel 690; Inconel 800). Carbon steels can be individually distinguished by the intensity ratio of chromium to iron and molybdenum to iron emission lines observed at the wavelength raging from 485 to 575 nm. Type 316 stainless steel can be easily differentiated from type 304 by identification of the molybdenum emission lines at an emission wavelength ranging from 485 to 575 nm: type 304 does not give any molybdenum emission lines, but type 316 does. The inconel alloys can be individually distinguished by the intensity ratio of Cr/Fe and Ni/Fe emission lines at the wavelength raging from 420 to 510 nm. TRELIBS has been proved to be a powerful analytical technique for direct analysis of alloys due to its non-destructivity and simplicity.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.11 no.4
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• pp.54-61
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• 2002

Inconel 690 alloy has widely been used in power plant and high temperature facilities because it has high thermal resistance and toughness. But we have little design data about the creep behaviors of the alloy. Therefore, in this study, an apparatus has been designed and built for conducting creep tests under constant load conditions. A series of creep tests on Inconel 690 alloy have been performed to get the basic design data and life prediction of inconel products and we have gotten the following results. First, the stress exponents decrease as the test temperatures increase. Secondly, the creep activation energy gradually decreases as the stresses become bigger. thirdly, the constant of Larson-Miller Parameters on this alloy is estimated about 10. And last the fractographs at the creep rupture show both the ductile and the brittle fracture according to the creep conditions.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.27 no.3
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• pp.357-362
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• 2003

Recently, the demand for advanced technology of high precision and high efficiency processing of hard materials such as inconel is increasing with progress of industrial goods. However, the machinability of inconel is very inferior to the other conventional industrial materials and the machining technology for inconel involves many problems to be solved in machining accuracy, machining efficiency, etc. Therefore it is needs to establish the machining technology. The purpose of this study is to develop an advanced ultrasonic vibration machining technology for inconel, using the 60KHz and 75KHz high frequency, amplitude about 8${\mu}{\textrm}{m}$ and 4${\mu}{\textrm}{m}$, respectively. As the result, this new ultrasonic vibration machining is reasonable and suitable for the high efficient. accuracy machining method of inconel.

• Proceedings of the KSME Conference
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• 2003.04a
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• pp.49-54
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• 2003

Most of the operating pressurized water reactors (PWRs)has chosen Inconel 600 as steam generator tubing. The long-term operation of steam generators showed that the use of this material induced localized corrosion damages. The current trend is using Inconel 690 as a tube material for the replacement steam generators. Based on the current trend, we have chosen Inconel 690 for the advanced Power Reactor 1400 (APR1400) steam generator tube material. In this paper, we examined the technical consideration in this modification: the effect of chemical composition, thermal conductivity, corrosion resistance and wear characteristics