• Title/Summary/Keyword: Iron content

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The Effects of Si and Mo on the Structures and Mechanical Properties in High Si Spheroidal Graphite Cast Iron (고 Si 구상흑연주철의 조직과 기계적성질에 미치는 Si과 Mo의 영향)

  • Kim, Jong-Yeon;Ra, Hyung-Yong
    • Journal of Korea Foundry Society
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    • v.10 no.3
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    • pp.225-234
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    • 1990
  • Spheroidal graphite cast irons which are Fe-3%C-(4-6)%Si-(0-0.5)%Mo were studied to improve not only heat resistance but also mechanical properties. With increasing Mo content, the graphitization was decreased and carbide volume fraction was increased. The graphite spheroidization ratio was not decreased in Fe-3%C-6%Si-Mo system cast iron with increasing Mo content, but that was decreased in Fe-3%C-4%Si-Mo system and Fe-3%C-5%Si-Mo system cast irons. Hardness was increased with the Si and Mo contents. At constant Si content, tensile strength was increased with increasing Mo content, but that was decreased at 6%Si. In the experiment of oxidation, weight gain was decreased as the Si and/or Mo content increased, but increased at 1.5%Mo content.

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Characteristics of Expression according to Iron Oxide Content in Ceramic Glaze (도자기 유약 내 철산화물 함량에 따른 흑유 발현 특성)

  • Choi, Jae Won;Han, Min Su
    • Journal of Conservation Science
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    • v.36 no.5
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    • pp.393-404
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    • 2020
  • We observed changes in the properties of the glaze layer according to the content of iron oxide and inferred the composition, content, and environment of the materials used in the past during the production process of black ware. First, experiments were conducted using different ratios of iron oxide, feldspar, calcite, and ash at different temperatures and firing environments; the characteristics of glaze were classified into five groups in the oxidation environment. Different properties were identified in the reducing environment above 1200℃. The crystal identified in the experiment was similar to the glaze characteristics in the excavated black ware. The crystal phase appeared in four groups: band shape, circular, arborescent phase, and needle crystal, depending on the change in the content of iron oxide. However, the difference in crystals did not appear significantly at high temperatures. In addition, crystals of glaze were divided into two groups depending on the component ratio. The presence or absence of feldspar is thought to affect crystallinity and amorphous iron oxide and the changes in the glaze layer changed substantially depending on the amount of iron oxide. In particular, it was confirmed that the aspects of iron oxide in the oxidation and reduction environments were different and, therefore, crystallization due to the firing environment also affected the optical characteristics.

Corrosion Behavior of Galvanized Steels with Outdoor Exposure Test in Korea for 36 Months (36개월간 국내 옥외폭로시험에 따른 아연도강의 부식거동)

  • Kim, K.T.;Kim, Y.S.
    • Corrosion Science and Technology
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    • v.17 no.5
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    • pp.231-241
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    • 2018
  • Atmospheric corrosion is generally an electrochemical degradation process of metal. It can be caused by various corrosion factors of atmospheric component, weather, and air pollutants. Moisture, particles of sea salts, and sulfur dioxide are major factors in atmospheric corrosion. Galvanizing coating is one of the most efficient ways to protect iron from corrosion by zinc plating on the surface of the iron. Galvanized steels are being widely used in automobiles, building structures, roofing, and other industrial structures due to their high corrosion resistance compared to bare iron. Atmospheric corrosion of galvanized steel has shown complex corrosion behavior depending on coating process, coating thickness, atmospheric environment, and air pollutants. In addition, different types and kinds of corrosion products can be produced depending on the environment. Lifespan of galvanized steels is also affected by the environment. Therefore, the objective of this study was to determine the corrosion behavior of galvanized steel under atmospheric corrosion at six locations in Korea. When the exposure time was increased, content of zinc from GA surface decreased while contents of iron and oxygen tended to increase. On the other hand, content of iron was constant even after 36 months of exposure of GI.

A Study on the Calcium and Iron Content of the Undaria pinnatifida suringar (미역중의 Calcium 및 Iron 의 함량에 대하여)

  • Rhee, Sook-Hee
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.1 no.1
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    • pp.25-31
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    • 1972
  • The Undaria pinnatifida collected in the waters of Dongbaek Island were grouped into young and adult ones and calcium and iron contents of each were analyzed by parts, i.e., separately for blade, stripe, and sporophyll by potassium permanganate titration method and spectrophotometric method respectively (O-phenanthrolin used). The results showed that the blades contain higher percentage of calcium than other parts both in young and adult seaweeds and that proportionately twice as much iron is contained in the blades than in the stripes.

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An experimental archaeological study on the Baekjae iron smelting furnace and its production process (백제 제철로 및 제철기술의 복원을 위한 실험 고고학적 연구)

  • Lee, Eun Woo;Han, Ji Seon;Chae, Mi Hui;Kim, Eun Ji
    • Korean Journal of Heritage: History & Science
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    • v.48 no.4
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    • pp.138-153
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    • 2015
  • A Jincheon Seokjangri B23 furnace was reconstructed and iron smelting experiment was performed to investigate an ancient Baekjae iron production process. The work mainly described in this paper is the $1^{st}$ and $2^{nd}$ experiments among the several experiments carried out at Jungwon National Research Institute of Cultural Heritage. Iron ore(magnetite) and oak charcoal were used as a source and a foot bellow was used for air supply. Common results of the experiments are masses of iron, slag and charcoal formed in the furnace. Most iron lumps were formed nearby the tuyere rather than the area of tapping hole. Metallographic and chemical analysis shows that the iron lumps can be used for either forge or cast depending on their carbon content. Low Fe content and glassy texture of the inner slags suggest that the operation environment was quite reducing. Based on the results of the iron smelting experiments, measurements and analysis, various information was obtained regarding physical-chemical and metallurgical processes of the ancient iron smelting process. It is firmly believed that its undisclosed contents can be revealed more in depth with continual reconstitution experiments.

The Effects of Sb Additions on the Structures and Mechanical Properties of C/V Graphite Cast Iron (C/V 흑연주철(黑鉛鑄鐵)의 조직(組織)과 기계적성질(機械的性質)에 미치는 Sb첨가효과(添加效果))

  • Choi, Yang-Jin;Kang, In-Chan
    • Journal of Korea Foundry Society
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    • v.7 no.1
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    • pp.53-59
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    • 1987
  • In order to study the infuence of Sb addition on the compacted vermicular graphite cast iron(C/V) and gray cast iron(GC), these specimen which had different Sb content(0-0, 1wt.%) were prepared. these specimen were tested for microstructure and mechanical properties. The result from this study are as follows. For C/V and GC, the microstructure of graphite appeared to be finer with increasing Sb content more than 0.06wt.% Ferrite disappeared from the matrix with addition of Sb more than 0.06wt.% in GC and more than 0.08wt.% in C/V. The size of the eutectic cell in GC was 4.5 to 7 times larger than that in C/V, but the decreasing tendancy of its size was more remarkable in GC than in C/V with increasing Sb content. The abrasion speed corresponding to the maximum amount of abrasion in the nabrasion test was found to be 1.37m/sec. GC sample weared 3.6 to 21 times faster than those of C/V did. the amount of abrasion demeased remarkably with Sb addition, and the abrasion rate was constant with Sb content over 0.04wt.%

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Study on the effect of silicon content on matrix of hypo-eutectic Cr alloyed cast iron (아공정(亞共晶)Cr 주철(鑄鐵)의 기지조직(基地組織)에 미치는 Si의 영향(影響))

  • Kim, Sug-Won;Lee, Oh-Yeon;Kim, Dong-Keon
    • Journal of Korea Foundry Society
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    • v.4 no.2
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    • pp.96-101
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    • 1984
  • The morphologies of eutectic cell formed during solidification affect on the mechanical properties in high Cr cast iron. In order to investigate the influence of Si on the structure, five kinds of specimen containing 16.42% Cr with varying amount of Si (0.51%, 1.17%, 2.22%, 2.71%, 3.56%) were poured into shell mould preheated $330^{\circ}C$ at $1510^{\circ}C$. The effect of Si on matrix in hypo-eutctic Cr cast iron (2.48% C, 16.42%) were studied through its mechanical tests and observation of microstructure using of metallurgical microscope, EPMA, SEM and Image analyzer systematically. The results obtained from the above studies are as follows: 1. Because of ${\Delta}T$ decreasing with increasing Si content, the morpologies of colony change into uniform bar-type carbide from plate-type ones, moreover eutectic colony size (Ew) becomes narrow and spacing of carbide wider. 2. As Si content increases, the amount of carbides also increases and most of Cr were dissolved in carbides while Si in matrix. 3. The hardness, tensile strength and wear resistance were increasing while impact value decreased with increasing Si content. 4. In fracture section, small amount of dimple pattern was observed in less than 1.17% Si but more than 2.22% Si river pattern was presented.

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Characteristic of Iron Oxide and the Magnetic Properties of Sr-ferrite by Roasting Temperature of Iron Oxide (산화철 배소에 따른 분체 특성 및 Sr-ferrite 자석의 소결 특성)

  • Jang Se-Dong
    • Resources Recycling
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    • v.12 no.6
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    • pp.19-25
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    • 2003
  • This experiment was carried out to examine the effect of iron oxide roasting for Sr-ferrite magnet. Chloride content was decreased with raising the 2 nd roasting temperature of iron oxide for ruthner process iron oxide. The optimization temperature for roasting of ruthner process iron oxide was around $800^{\circ}C$ as average particle size 1.5∼1.9 $\mu\textrm{m}$, apparent bulk density 1.4 g/$m\ell$ and chloride content 0.05%. The relation between Br and HcJ by sintering temperature for Sr-ferrite magnet was found to be Br≒-0.258HcJ+494. In case of having a vibrating disk mill for the ruthner process iron oxide, the magnetic properties were Br 421 mT and HcJ 251 kA/m.

The study of manganese removal mechanism in aeration-sand filtration process for treating bank filtered water (강변여과수 처리를 위한 포기-모래여과공정에서 망간제거 기작에 관한 연구)

  • Choi, Seung-Chul;Kim, Se-Hwan;Yang, Hae-Jin;Lim, Jae-Lim;Wang, Chang-Keun;Jung, Kwan-Sue
    • Journal of Korean Society of Water and Wastewater
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    • v.24 no.3
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    • pp.341-349
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    • 2010
  • It is well known that manganese is hard to oxidize under neutral pH condition in the atmosphere while iron can be easily oxidized to insoluble iron oxide. The purpose of this study is to identify removal mechanism of manganese in the D water treatment plant where is treating bank filtered water in aeration and rapid sand filtration. Average concentration of iron and manganese in bank filtered water were 5.9 mg/L and 3.6 mg/L in 2008, respectively. However, their concentration in rapid sand filtrate were only 0.11 mg/L and 0.03 mg/L, respectively. Most of the sand was coated with black colored manganese oxide except surface layer. According to EDX analysis of sand which was collected in different depth of sand filter, the content of i ron in the upper part sand was relatively higher than that in the lower part. while manganese content increased with a depth. The presence of iron and manganese oxidizing bacteria have been identified in sand of rapid sand filtration. It is supposed that these bacteria contributed some to remove iron and manganese in rapid sand filter. In conclusion, manganese has been simultaneously removed by physicochemical reaction and biological reaction. However, it is considered that the former reaction is dominant than the latter. That is, Mn(II) ion is rapidly adsorbed on ${\gamma}$-FeOOH which is intermediate iron oxidant and then adsorbed Mn(II) ion is oxidized to insoluble manganese oxide. In addition, manganese oxidation is accelerated by autocatalytic reaction of manganese oxide. The iron and manganese oxides deposited on the surface of the sand and then are aged with coating sand surface.

Increased expression of the F1Fo ATP synthase in response to iron in heart mitochondria

  • Kim, Mi-Sun;Kim, Jin-Sun;Cheon, Choong-Ill;Cho, Dae-Ho;Park, Jong-Hoon;Kim, Keun-Il;Lee, Kyo-Young;Song, Eun-Sook
    • BMB Reports
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    • v.41 no.2
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    • pp.153-157
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    • 2008
  • The objective of the present study was to identify mitochondrial components associated with the damage caused by iron to the rat heart. Decreased cell viability was assessed by increased presence of lactate dehydrogenase (LDH) in serum. To assess the functional integrity of mitochondria, Reactive Oxygen Species (ROS), the Respiratory Control Ratio (RCR), ATP and chelatable iron content were measured in the heart. Chelatable iron increased 15-fold in the mitochondria and ROS increased by 59%. Deterioration of mitochondrial function in the presence of iron was demonstrated by low RCR (46% decrease) and low ATP content (96% decrease). Using two dimensional gel electrophoresis (2DE), we identified alterations in 21 mitochondrial proteins triggered by iron overload. Significantly, expression of the $\alpha$, $\beta$, and d subunits of $F_1F_o$ ATP synthase increased along with the loss of ATP. This suggests that the $F_1F_o$ ATP synthase participates in iron metabolism.