• Title/Summary/Keyword: Iron compound

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Improving of Corrosion Resistance of Aluminum Alloys by Removing Intermetallic Compound

  • Seri, Osami
    • Corrosion Science and Technology
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    • v.7 no.3
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    • pp.158-161
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    • 2008
  • It is well known that iron is one of the most common impurity elements found in aluminum and its alloys. Iron in the aluminum forms an intermetallic compounds such as $FeAl_3$. The $FeAl_3$ particles on the aluminum surface are one of the most detrimental phases to the corrosion process and anodizing procedure for aluminum and its alloys. Trial and error surface treatment will be carried out to find the preferential and effective removal of $FeAl_3$ particles on the surfaces without dissolution of aluminum matrix around the particles. One of the preferable surface treatments for the aim of getting $FeAl_3$ free surface was an electrochemical treatment such as cathodic current density of $-2kAm^{-2}$ in a 20-30 mass% $HNO_3$ solution for the period of 300s. The corrosion characteristics of aluminum surface with $FeAl_3$ free particles are examined in a $0.1kmol/m^3$ NaCl solution. It is found that aluminum with free $FeAl_3$ particles shows higher corrosion resistance than aluminum with $FeAl_3$ particles.

A Study on Coating Adhesion of Hot Rolled Galvanized Iron Manufactured without pickling process (산세생략형 열연 용융아연도금강판의 특성)

  • 최진원;전선호
    • Journal of the Korean institute of surface engineering
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    • v.32 no.1
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    • pp.21-30
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    • 1999
  • Coating adherance behavior of low carbon steels, produced by POSCO, Korea, was studied in order to study the characteristics of hot rolled galvanized iron(HGI) manufactured without pickling line and the development of its process. Galvanizing experiments were carried out in zinc pot with 0.2wt% Al after hot rolled plates with scale were reduced at $550~750^{\circ}C$ in 10~30% hydrogen gas atmosphere during 60~400seconds. The reduced plates and coated products were examined by SST, XRD, SEM and EPMA on their surfaces and cross sections. Coating layer of HGI manufactured with pickling line was composed of retained scale, Fe-Zn-Al compound, Fe-Zn compound ($\delta_1\;and\;\zeta$ Phase) and pure zinc. It was superior to HGI in coating adhesion. It seems to be due to forming of Fe-Zn-Al compound in interface of matrix and retained porous scale.

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A Study on the Metallurgical Characteristic of Hammer Scale Produced through Traditional Iron-making Experiments (전통 제철실험을 통해 생산된 단조박편의 재료과학적 특성 연구)

  • Cho, Sung Mo;Cho, Nam Chul
    • Journal of Conservation Science
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    • v.37 no.6
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    • pp.738-747
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    • 2021
  • This study attempted to investigate the metallurgical characteristic through material scientific analysis of hammer scale produced as a direct smelting method restoration experiment for each raw material of iron. To this end, four hammer scale groups were set up, respectively, by experimenting with Gyeongju-Gampo Iron sand and Yangyang Iron ore. For the analysis, principal component analysis, compound analysis, microstructure observation, and chemical composition were confirmed. As a result of principal component analysis, as forging and refining progressed, the content of Fe increased and the content of non-metallic objects decreased. As a result of compound analysis, iron oxide-based compounds were identified. As a result of confirming microstructure and chemical composition, Wüstite and Fayalite were observed overall, and agglomerated Wüstite were observed in some. Magnetite on shape of polygon and pillar was observed. In addition, it was confirmed that internal defects, impurities, and non-metallic interventions gradually decreased. In the future, it is necessary to investigate the metallurgical characteristic through material scientific analysis of hammer scale produced through restoration experiments using various raw material of iron, and compare them with those excavated from Iron manufacture ruins.

Studying the Effect of Cation to the Formation of Iron Oxyhydroxide (양이온 성분이 수산화철 형성에 미치는 영향 조사)

  • Oh, Sei-Jin;Lee, Jae-Yong;Kwon, Soon-Ju;Yoo, Jang-Yong;Choo, Wung-Yong
    • Korean Journal of Materials Research
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    • v.12 no.10
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    • pp.796-802
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    • 2002
  • Effect of nine different cations to the formation of iron oxyhydroxide was studied using Mossbauer spectroscopy, XRD and BET. The Redox Potential and pH were measured for the determination of the internal reaction rate, as well. The phases of iron oxyhydroxide could not be the same with each other, due to the present of different cations in solution. Although the oxyhydroxide compound were composed of the same phases, the fraction of each phase was different from each other. The internal reaction rate was varied by the substitution of cation. It could be a cause of the different phase and particle size of oxyhydroxide compound.

The Development of Estimation Model for Iron Compound Originated from Anaerobic Microbial Corrosion (혐기성 미생물부식에 의해 생성되는 철화합물 추정식 개발)

  • Jeon, Seok-Jun
    • Journal of Korean Society on Water Environment
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    • v.18 no.4
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    • pp.379-386
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    • 2002
  • In this study, estimation model for iron compound originated from upflow, anaerobic fixed bed reactor, which treats sewage domestic wastewater, was developed. The estimation model was formulated by a mathematical expression which was based on the mass balance. Below the HRT of 60 minute, sulfide concentration combining with iron $FeS_2$ is the highest because the maximum sulfate consumption rate $V_{maxS}$ and half-saturation constant of sulfate $K_{mS}$ exert an important effect on the estimation model as temperature was increased. But increment of $FeS_2$ concentration is weakened above the HRT of 60 minutes and represent the lowest value at the HRT of 108 minutes. It implies that liquid phase distribution ratio of sulfide ${\alpha}r$ becomes lower as temperature was increased. While phosphorus concentration combining with iron $Fe_3(PO_4)_3$ is increased as HRT and temperature are increased, which is affected by phosphorus removal rate constant $k_p$. As the result of estimating the iron concentrations of corrosion by the model, the concentration of iron corrosion is higher than any other at the HRT of 108 minute and $20^{\circ}C$. The predicted values were compared with measured ones at different HRT(13.5, 27, 54, 108 min) and temperature(20, 25, $30^{\circ}C$). The experimental data could be fitted with the simulated curves. Therefore, the mathematical expression could be applicable to design full-scale wastewater treatment plants.

Effects of Cu and Zr Addition on the Tensile Properties, Corrosion Characteristics and Interfacial Compounds with Cast Iron of Al-Si-Mg Alloy for Compound Casting (복합주조용 Al-Si-Mg 합금의 인장성질, 부식특성 및 주철과의 접합계면 화합물에 미치는 Cu 및 Zr 첨가의 영향)

  • Kyoung-Min Min;Ki-Chae Jung;Je-Sik Shin;Jeong-Min Kim
    • Korean Journal of Materials Research
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    • v.33 no.1
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    • pp.8-14
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    • 2023
  • In order to broaden the range of application of light weight aluminum alloys, it is necessary to enhance the mechanical properties of the alloys and combine them with other materials, such as cast iron. In this study, the effects of adding small amounts of Cu and Zr to the Al-Si-Mg based alloy on tensile properties and corrosion characteristics were investigated, and the effect of the addition on the interfacial compounds layer with the cast iron was also analyzed. Although the tensile strength of the Al-Si-Mg alloy was not significantly affected by the additions of Cu and Zr, the corrosion resistance in 3.5 %NaCl solution was found to be somewhat lowered in this research. The influence of Cu and Zr addition on the type and thickness of the interfacial compounds layer formed during compound casting with cast iron was not significant, and the main interfacial compounds were identified to be Al5FeSi and Al8Fe2Si phases, as in the case of the Al-Si-Mg alloys.

Effects of Kimchi Consumption on Iron Status in Adult Male Volunteers (김치의 섭취가 성인 남성의 철분영양상태 지표에 미치는 영향)

  • 오영주
    • Journal of Nutrition and Health
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    • v.30 no.10
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    • pp.1188-1194
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    • 1997
  • The aim of this was to investigate whether the regular consumption of kimchi influences the iron status (RBC , Hb, Ht, MCH, MCV, MCHC, transferrin , serum iron, and ferritin) in volunteers. Healthy male adults(n=12) took part in the study subdivided into the control Ⅰ-phase(for 2weeks), kimchi-phase (for 4 weeks), and control Ⅱ-phase(for 2 weeks). In addition to their normal diet, participant consumed 300g of lactic acid fermented Chinese cabbage kimchi daily for four weeks. In the control Ⅰ and control Ⅱ phases, the participants kept up their normal diets without consuming any fermented foods. Dietary intakes were recorded for 3 consecutive days in each phase, with the aid of household measures. Every two weeks. blood specimens were analysed. Significant differences(p<0.05) between the phases were found in MCHC, and transferrin in blood were not significantly changed during kimchi consumption. However, serum iron and ferritin levels were significantly increased(p<0.05) during kimchi consumption, achieving the highest levels in the fourth week of the kimchi components(ascrobic acid, sulfer compound, organic acid, capsaicin, gingerol , allicin). Because of lacticacid fermented kimchi's potential to prevent anemia , the consumption of this food can be recommended.

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Two Neuroprotective Compounds from Mushroom Daldinia concentrica

  • Lee, In-Kyoung;Bong-Sik Yun;Young-Ho Kim;Ick-Dong Yoo
    • Journal of Microbiology and Biotechnology
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    • v.12 no.4
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    • pp.691-691
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    • 2002
  • In the course of our screening for neuroprotective agents, a new compound (1) was isolated together with a known compound, caruilignan C (2), from the fruiting body of Daldinia concentrica. Their structures were determined on the basis of various spectral studies. Both compounds exhibited neuroprotective effect against iron-induced neurodegeneration in a primary culture of mouse cortical neurons.

Two Neuroprotective Compounds from Mushroom Daldinia concentrica

  • Lee, In-Kyoung;Yun, Bong-Sik;Kim, Young-Ho;Yoo, Ick-Dong
    • Journal of Microbiology and Biotechnology
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    • v.12 no.4
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    • pp.692-694
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    • 2002
  • In the course of our screening for neuroprotective agents, a new compound (1) was isolated together with a known compound, caruilignan C (2), from the fruiting body of Daldinia concentrica. Their structures were determined on the basis of various spectral studies. Both compounds exhibited neuroprotective effect against iron-induced neurodegeneration in a primary culture of mouse cortical neurons.