• 한국표면공학회지
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• 제13권2호
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• pp.81-86
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• 1980

The mechanical properties of aluminized steel were investigated after the JIS SB 41 plates were dipped in molten aluminum bath. (1) The growth rate of iron-aluminum alloy layer was fast in early stage of alumizing, and then gradually decreased with increasing time. However, over the time period above 10 minutes the growth of alloy layer did not occur. (2) The constituent of alloy layer formed on the steel surface was identified to be intermetallic compound of $Fe_2\;Al_5$. (3) The ultimate tensile strength and elongation of aluminized steel showed a nearly constant value over all thickness below about 0.15 mm. However, both properties decreased rapidly in showed a nearly constant value over all thickness above about 0.20 mm. (4) In case of aluminized steel with greater thickness, crack was formed below yield point of base metal, which is considered to be attributed to the alloy layer failure.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2018년도 추계 학술논문 발표대회
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• pp.173-174
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• 2018

In this study, the objective of this study was to evaluate the adhesive characteristics of existing self-adhesive rubber asphalt sheet, butyl sheet and acrylate sheet in a low temperature environment through Tack Rolling Ball Test to obtain basic data on acrylate. As a result of this experiment, in the case of the self-molding rubber asphalt sheet and the butyl rubber sheet, the compound of the sheet was frozen in the low temperature environment and the iron bead was separated. On the other hand, the acrylate sheet did not freeze the acrylate even at 0 ℃, It is confirmed that the measured value is shown by Ball Test.

• 한국재료학회지
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• 제18권3호
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• pp.143-147
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• 2008

Fe compounds in scoria as distributed in the south-western area of Jeju Island were investigated using X-ray fluorescence spectroscopy, X-ray diffractometry, and $^{57}Fe$ $M{\ddot{o}}ssbauer$ spectroscopy. The samples were prepared from four parasite volcanoes. It was found that these samples are typical basalt comprised of $SiO_2$, $Al_2O_3$, Fe, and silicate minerals. The $M{\ddot{o}}ssbauer$ spectra showed doublets for olivine, pyroxene, and ilmenite as well as sextets for hematite and magnetite. The valence state of Fe is chiefly a 3+ charge state with a slight 2+ charge state. It is expected that these results will add to the body of information related to the formation mechanisms of Jeju Island.

• Journal of Magnetics
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• 제5권4호
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• pp.124-129
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• 2000

$Sm_2Fe_{17}N_x$ film magnets were prepared using a $Sm_2Fe_{17}$ target in a $N_2$ gas atmosphere using a Nd-YAG pulsed laser ablation technique. The effect of nitrogen pressure, deposition temperature, pulse time and film thickness on the structure and magnetic properties of $Sm_2Fe_{17}N_x$ film were studied. Increasing the nitrogen pressure up to 5 atm led to the formation of complete $Sm_2Fe_{17}N_x$ compound. Optimized magnetic properties with the nitrogenation temperature in the range 500-53$0^{\circ}C$ could be obtained by extending the nitrogenation time up to 4 hours. Relatively low coercivities of 400~600 Oe were found in $Sm_2Fe_{17}N_x$films 50~100 m thick, while a $4\piM_s$ of 10$\sim$12 kG could be achieved. In-plane anisotropy, which was the basic goal in this study, was achieved by controlling the nitrogenation parameters.

• 약학회지
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• 제13권2_3호
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• pp.88-92
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• 1969

As a part of series of "Studies on Inorganic Chinese Drugs in Korea" four arsenic mineral Chinese drugs were analyzed by emission spectrographic method, and also were studied crystallographically by X-ray diffraction method. The following results were revealed: 1) Tang-shin-suk was not a Native arsenic but a Arsenolite which containing 94% of $As_{2}O_{3}$, 2) Toh-shin-suk was Crade Aluminum silicate 3) Woong-whang was a Realgar $As_{2}S_{2}$, 4) Yeh-suk was a Ca-Al-Silicate which was mixed with .alpha.-quartz contaminated by Iron compound and trace amount of Arsenic. It was not verified that the presence of Arsenopyrite FeAsS which has been believed as a main component of Yeh-suk by a Japanese author Wakimizu, nor the presence of Arsenolite which was reported by Masutomi.

• Corrosion Science and Technology
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• 제21권1호
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• pp.21-31
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• 2022

Potentiodynamic polarization, EIS measurements, quantum chemical calculations, and molecular dynamic simulations were used to investigate the corrosion behavior of mild steel in 0.5 M aqueous hydrochloric acid medium in the presence or absence of nystatin drug. Potentiodynamic tests suggested that this molecule could act as a mixed inhibitor due to its adsorption on the mild steel surface. The objective of this study was to exploit theoretical calculations to gain a better understanding mechanism of inhibition. Calculating the adsorption behavior of the investigated molecule on Fe (1 1 0) surface was accomplished using Monte Carlo simulation. Molecules were also investigated using Density Functional Theory (DFT), specifically PBE functional, in order to identify the link between molecular structure and corrosion inhibition behavior of the compound under investigation. Adsorption energies between nystatin and iron were estimated more accurately by utilizing Molecular Mechanics calculation with Periodic Boundary Conditions (PBC). Estimated theoretical parameters significantly assisted our understanding of the corrosion inhibition mechanism exhibited by this molecule. They were found to be in accord with experimental results.

• 한국표면공학회지
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• 제32권2호
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• pp.157-164
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• 1999

In this study the effect of nickel addition on the coating weight of mini-mill steels containing silicon has been studied. It is shown that the pure zinc accelerated growth of the alloy layers occurred by a rapid growth of the zeta phase at 0.06%Si. The addition of 0.06%Ni to a pure zinc bath was found to be very effective in reducing the coating weight and promoting preferential development of the delta phase. The coating obtained by immersion in the Zn-Ni bath shows the presence of a nickel-rich region between the zeta phase and the eta phase. It is suggested that nickel prevents the rapid growth of the zeta phase due to the formation of the Zn-Ni-Fe ternary compound, which may act as a barrier to inward diffusion of zinc or iron at the zeta-eta boundary.

• 보존과학회지
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• 제33권4호
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• pp.297-312
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• 2017

고대 제철 공정에서 원광석 내의 철과 기타 광물의 분리가 원활하게 이루어질 수 있도록 조재제를 첨가하는 경우가 많다. 하지만 조재제 첨가 유무를 판단할 수 있는 정확한 기준이 될 만한 자료가 부족한 실정이다. 따라서 본 연구에서는 조재제 첨가에 따라 달라지는 슬래그의 재료학적 특성을 파악하기 위해 제련 실험을 진행하였다. 총 3차례 진행된 실험에서 산출된 슬래그의 미세조직을 관찰하고 성분을 분석하였다. 1차 실험은 조재제를 첨가하지 않았으며, 산출된 슬래그의 전철량은 39.45~52.94 wt%로 확인되었다. 조재제를 첨가한 2, 3차 실험에서는 34.89~38.92 wt%로 감소하였다. 미세조직 분석 결과 2, 3차 실험에서는 철산화물 이외에 Gehlenite, Hercynite와 같은 CaO 화합물이 나타난다. 비금속개재물 성분 간 비율을 비교한 결과, 1차 실험의 유리질바탕의 $CaO/SiO_2$ 값이 0.42를 기준으로, 이보다 높을 경우 조재제를 첨가하였을 것으로 판단된다. $Al_2O_3/SiO_2-CaO/SiO_2$ 비교 분석한 결과, $Al_2O_3-SiO_2$ 비율은 유사한 제련공정 시스템(원광, 노벽, 연료)을 판단하는 지표로 활용할 수 있을 것으로 본다.

• 공업화학
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• 제7권2호
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• pp.299-307
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• 1996

$10^{-6}{\sim}10^{-3}mol/{\ell}$ 농도범위에서 PO가 먼저 부가된 sodium poly(oxyethylene(EO), oxyisopropylene(PO)) dodecyl ether sulfates의 표면장력은 EO가 부가된 화합물보다 낮게 나왔다. 그리고 대체적으로 일반적인 음이온성계면활성제보다도 낮게 나왔다. PO가 먼저 부가된 화합물에 대하여 Gibbs' 흡착등온선으로 계산한 흡착능(${\Gamma}=2.2{\times}10^{-10}mol/cm^2$)은 EO가 부가된 화합물보다는 높지만 sodium dodecyl ether sulfate(${\Gamma}=3.2{\times}10^{-10}mol/cm^2$)보다는 낮다. 이러한 현상은 PO가 부가된 화합물의 분자량이 크기 때문으로 사료된다. 기포력, n-hexane과 benzene에 대한 유화력, 돼지기름과 소기름에 대한 세정력 그리고 산화철에 대한 분산성은 PO 화합물이 EO 화합물보다 우수하게 나타났다. 이러한 현상들은 친수성과 소수성 부분이 각각 따로 따로 존재할 때 계면활성이 높음을 의미한다. 수계에서 n-hexane과 benzene에 대한 유화력 측정결과는 n-hexane보다 benzene에 대하여 높게 나왔으며, 불규칙적인 분산특성을 나타내었다.

• 한국자기학회지
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• 제21권1호
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• pp.37-41
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• 2011

제주도 북동부 송당리 일원에 형성된 오름에서 채취한 스코리아의 화학적 조성 및 산화철의 원자가상태와 자기적 성질을 조사하였다. X-선 회절법을 이용하여 분석한 결과 이 지역의 스코리아들은 $SiO_2$와 장석이 주를 이루고 소량의 철 산화물이 확인되었다. M$\ddot{o}$ssbauer 분광법을 통해 광물 내의 철 성분들이 어떤 형태를 이루는지 살펴본 결과 olivine인 규산염과 pyroxene, ilmenite 형태의 상자성 철산화물 및 상온에서 반강자성 및 강자성 물질인 산화철 및 silicate mineral 등이 존재하였다. 철 화합물의 원자 가상태는 대부분 olivine과 pyroxene에서 $Fe^{3+}$이 존재하고 olivine, pyroxene과 ilmenite에 의해 소량의 $Fe^{2+}$ 성분이 존재하고 있음을 알 수 있었고. 그 외에도 산화철 및 silicate mineral로 추정되는 흡수선도 관측되었다. 따라서 이 지역 대부분의 스코리아내의 철에 대한 주 원자가 상태는 $Fe^{3+}$과 $Fe^{2+}$가 공존하는 것으로 분석되었다.