극저온 환경에 적용되는 INCONEL 718합금의 Gas Tungsten Arc Welding 기계적 특성 평가

김기홍,문인상,문일윤,이병호,Kim, Ki-Hong,Moon, In-Sang,Moon, Il-Yoon,Rhee, Byung-Ho 한국재료학회 2009 한국재료학회지 Vol.19 No.12

Inconel 718 alloy has excellent mechanical properties at room temperature, high temperature and cryogenic conditions. UTS of base metal is about 900MPa at room temperature; this is increased up to 1300MPa after heat treatment & aging-hardening. Mechanical properties of Inconel 718 Alloy were similar to those shown in the the results for tensile test; mechanical properties of Inconel 718 alloy's GTAW were similar to those of base metal's properties at room temperature. Mechanical properties at cryogenic conditions were better than those at room temperature. Heat-treated Inconel 718, non- filler metal GTAW on Inconel 718 and GTAW used filler metal on Inconel 718's UTS was 1400MPa at cryogenic condition. As a result, the excellent mechanical properties of Inconel 718 alloy under cryogenic conditions was proved through tensile tests under cryogenic conditions. In addition, weldability of Inconel 718 alloy under cryogenic conditions was superior to that of its base-metal. In this case, UTS of hybrid joint (IS-G) at -100$^{\circ}C$ was 900MPa. Consequently, UTS of Inconel 718 alloy is estimated to increase from -100$^{\circ}C$ to a specific temperature below -100$^{\circ}C$. Therefore, Inconel 718 alloy is considered a pertinent material for the production of Lox Pipe under cryogenic conditions.

Evaluation of Tool Life in the Dry Machining of Inconel 718 Parts from Additive Manufacturing (AM)

Eunju Park,Dong Min Kim,Hyung Wook Park,Young-Bin Park,Namhun Kim 한국정밀공학회 2020 International Journal of Precision Engineering and Vol.21 No.1

The need for developing sustainable manufacturing processes are more and more increasing due to environmental regulations that are introduced worldwide. In the field of manufacturing metallic parts, the dry machining process is the effective way to reduce the costs of production and to avoid harm in environment and human health. Especially, Inconel 718 parts, which is very popular in aerospace, chemical, and nuclear industries, produced with additive manufacturing require a finishing process for quality assurance to rough and porous surfaces after printing process. Generally, machining of difficult-to cut materials such as Inconel 718 need the cutting fluids to improve the surface integrity and tool life. The present work investigates the effect of microstructure life of the Inconel 718 part produced by additive manufacturing on the tool compared with the wrought Inconel 718 part during the dry machining. The experimental findings show that the tool life of the Inconel 718 from AM is increased due to the melt pool microstructure formed by the laser irradiation though the hardness is higher than the wrought Inconel 718. Abrasive wear is strongly affected to tool life of the Inconel 718 from AM while adhesive and fracture wear is mostly found in the tool of wrought Inconel 718.

Ti-6Al-4V 합금 기지 위에 FGM 방식으로 적층제조 된 Inconel 718의 접합 특성 분석

박찬웅,박진웅,정기채,이세환,김성훈,김정한,Park, Chan Woong,Park, Jin Woong,Jung, Ki Chae,Lee, Se-Hwan,Kim, Sung-Hoon,Kim, Jeoung Han 한국분말재료학회 (*구 분말야금학회) 2021 한국분말재료학회지 (KPMI) Vol.28 No.5

In the present work, Inconel 718 alloy is additively manufactured on the Ti-6Al-4V alloy, and a functionally graded material is built between Inconel 718 and Ti-6Al-4V alloys. The vanadium interlayer is applied to prevent the formation of detrimental intermetallic compounds between Ti-6Al-4V and Inconel 718 by direct joining. The additive manufacturing of Inconel 718 alloy is performed by changing the laser power and scan speed. The microstructures of the joint interface are characterized by scanning electron microscopy, energy-dispersive X-ray spectroscopy, and micro X-ray diffraction. Additive manufacturing is successfully performed by changing the energy input. The micro Vickers hardness of the additive manufactured Inconel 718 dramatically increased owing to the presence of the Cr-oxide phase, which is formed by the difference in energy input.

저온 분사 공정을 이용해 적층된 INCONEL 718의 계면접합 저해요인 분석

김재익(Jaeick Kim),이승태(Seungtae Lee),이창희(Changhee Lee) 한국표면공학회 2015 한국표면공학회지 Vol.48 No.6

The cost for maintenance (replacement cost) of Ni-superalloy components in plant industry is very expensive because of high unit price of INCONEL 718. A development of repairing technology using kinetic spray process can be very helpful for reducing the maintenance cost. However, it is very difficult to produce welldeposited INCONEL 718 layer showing high interfacial bond strength via kinetic spraying. Thus, INCONEL 718 was deposited on SCM 440 substrate and the interfacial properties were investigated, in order to elucidate the cause of hindrance to the bonding between INCONEL 718 layer and SCM 440 substrate. As a result, it was revealed that the dominant obstacle to the interfacial bonding was excessive compressive residual stress accumulated in the coating layer, resulting from low plastic-deformation susceptibility of INCONEL 718. Nevertheless, the bonding state was enhanced by the post heat-treatment through relieving the residual stress and generating a diffusion/metallurgical bonding between the INCONEL 718 deposit and SCM 440 substrate.

극저온 환경에 적용되는 INCONEL 718합금의 GTAW 기계적 특성 평가

김기홍(Kihong Kim),문인상(Insang Moon),이병호(Byungho Rhee),이수용(Sooyong Lee) 한국추진공학회 2009 한국추진공학회 학술대회논문집 Vol.2009 No.11

INCONEL 718합금은 상온, 고온 및 저온환경에서 기계적 특성이 아주 우수하다. 상온에서의 모재 강도는 약 900MPa이며, 열처리 후 시효경화처리에 의해 강도가 약 1300MPa까지 증가한다. 이러한 INCONEL 718합금의 기계적 특성은 시험결과에서도 유사한 값을 나타내었고, GTAW 용접부의 상온 기계적 특성도 모재보다 우수한 강도를 나타내었다. 또한 저온에서의 기계적 특성은 모든 시험조건에서 상온보다 높은 강도를 나타내었으며, 열처리 모재시편과 용접시편은 1400MPa에 달하는 고강도를 나타내었다. 이러한 결과를 바탕으로 INCONEL 718합금의 저온 기계적 특성이 우수한 것을 증명하였고, 용접성 또한 모재의 특성과 같이 상온 및 저온 특성이 우수한 것을 알 수 있었다. INCONEL 718 합금과 STS 316L의 이종접합의 경우에도 -100℃환경의 인장강도가 상온보다 300MPa 이상 증가하는 것을 알 수 있었다. 따라서, INCONEL 718합금은 100℃이하부터 일정온도까지는 기계적 특성이 계속 증가 할 것으로 사료되며, 극저온 고압 상태로 공급되는 산화제 배관 제작에 적합한 소재로 판단된다.

공구수명과 표면거칠기 특성 분석을 통한 인코넬 718의 가공성 평가

권해웅(Hae-Woong Kwon),강익수(IK-Soo Kang),김정석(Jeong-Suk Kim),문성준(Sung-Jun Moon),김기태(Ki-Tae Kim) 한국기계가공학회 2008 한국기계가공학회 춘추계학술대회 논문집 Vol.2008 No.-

Inconel alloys have been widely used in the aerospace, heavy industry and automotive. Inconel 718 alloy has been applied in high temperature, high load and corrosion resistant environments due to its superior properties. However, This alloy is a difficult-to-cut nickel-based superalloy. In this study, the machinability of Inconel 718 is investigated to improve tool life under various cutting conditions with UT coated tungsten carbide(WC) end mills. . The tool life on the basis of flank wear(0.2㎜) has been investigated in side cutting. The cutting conditions can be suggested to improve both the tool life and machined surface quality in Inconel 718 maching.

Gamma and neutron shielding properties of B 4 C particle reinforced Inconel 718 composites

Ugur G okmen 한국원자력학회 2022 Nuclear Engineering and Technology Vol.54 No.3

Neutron and gamma-ray shielding properties of Inconel 718 reinforced B4C (0-25 wt%) were investigatedusing PSD software. Mean free path (MFP), linear and mass attenuation coefficients (LAC,MAC), tenthvalueand half-value layers (TVL,HVL), effective atomic number (Zeff), exposure buildup factors (EBF),and fast neutron removal cross-sections (FNRC) values were calculated for 0.015e15 MeV. It was foundthat MAC and LAC increased with the decrease in the content of B4C compound by weight in Inconel 718. The EBFs were computed using G-P fitting method for 0.015e15 MeV up to the penetration depth of 40mfp. HVL, TVL, and FNRC values were found to range between 0.018 cm and 3.6 cm, between 2.46 cm and12.087 cm, and between 0.159 cm 1 and 0.194 cm 1, respectively. While Inconel 718 provides themaximum photon shielding property since it offered the highest values of MAC and Zeff and the lowestvalue of HVL, Inconel 718 with B4C(25 wt%) was observed to provide the best shielding material forneutron since it offered the highest FNRC value. The study is original in terms of several aspects;moreover, the results of the study may be used in nuclear technology, as well as other technologiesincluding nano and space technologies

Impurity Removal and Microstructural Analysis of Inconel 718 Refined by Hydrogen Plasma Arc Melting

Do Sung Lee,Jung‑Min Oh,Jun‑Ho Seo,Jae‑Won Lim 대한금속·재료학회 2021 METALS AND MATERIALS International Vol.27 No.7

The high-temperature melting and the removal of gaseous and metallic impurities from Inconel 718 by hydrogen plasma arcmelting (HPAM) were investigated. Solid-type Inconel 718 scraps were used as raw material. The concentrations of oxygen,nitrogen, and metallic impurities in the scraps were simultaneously decreased by HPAM. The refined ingot satisfied therecommended criteria for commercial Inconel 718. Following the melting of Inconel 718 by HPAM, the microstructure ofthe as-cast depended on different parts of the ingots, due to the different cooling rate of each part.

아크열원을 이용한 Inconel 718의 금속적층에서 SS 275 모재로의 대체 가능성 평가

이태현,오제훈,감동혁 대한용접접합학회 2019 대한용접·접합학회지 Vol.37 No.1

Additive manufacturing of novel metals has received much attention as an alternative to traditional manufacturing because of its high material efficiency, shorter lead time and higher design flexibility. However for most additive manufacturing base substrate were not considered in the calculations. Generally, the base substrate is applied in the same material or similar chemical component alloys. This is in addition to the feedstock and the cost of use since it is discarded after the process in the process of removing the base substrate after the process. Therefore, it is very important to minimize the cost of the base substrate and the use of cheaper and different materials should be considered. In this study, substitution of base substrate in the production of arc and wire additives using gas metal arc welding (GMAW) was evaluated. Inconel 718 was deposited on two different substrates (SS275, Inconel 718). In SS275 substrate, we observed that after three layers of deposition, the deposition width is similar to the thickness of the Inconel 718 substrates. It has also been found that dilution from the fourth deposition layer with respect to the SS275 substrate by examining the dilution from the viewpoint of the deposition layer can be solved by cutting the first three layers of the dilution problem.

고압절삭유를 이용한 인코넬 718 절삭가공의 공구마모 분석

김승기(Seung-Gi Kim),양기동(Gi-Dong Yang),박경희(Kyung-Hee Park),최헌종(Honzong Choi),이동윤(Dong-Yoon Lee) 대한기계학회 2017 대한기계학회 춘추학술대회 Vol.2017 No.11

Despite of low machinability of Inconel 718, its demand keeps increasing and many researches on the improvement of Inconel 718 machinability are being presented recently. The most serious problem on machining Nickel-based alloys is known to competitively short tool life. Many studies pointed out that the extremely high temperature near the cutting edge of a tool caused the short tool life. High pressure coolant was introduced as a good strategy for cooling the cutting tool edge, which could increase the cutting tool life. This paper presents the experimental results of milling Inconel 718 with high pressure coolant focusing on tool wear characteristics. Flank wear of used cutting tools after machining in various cutting conditions are measured and compared. General flood coolant case and high pressure coolant case are mainly compared. Uncoated insert case and PVD coated insert case are also compared and the wear maps for each case are presented. The experimental results show that the tool wear decreases 23% in the case of high pressure coolant case with PVD coated inserts, that is, tool life increases 11% in the same cutting condition.