Preparation of an ultrafine-grained Fe-40Al intermetallic compound

An ultrafine grained Fe-40Al intermetallic compound is fabricated by a selfpropagating high temperature synthesis(SHS) casting.The XRD result shows that the Fe-40Al intermetallic compound consists of the B2 FeAl phase.The Fe-40Al intermetallic compound presents ultrafine grain size in the range of 100-600 nm,leading from the high nucleation rate and the low growth rate.The Fe-40Al intermetallic compound exhibits high hardness(3.4 GPa) and high bending strength(830 MPa) and high compressive strength(2700 MPa...     

An ultrathin polymer coating of carboxylate self-assembled monolayer adsorbed on passivated iron to prevent iron corrosion in 0.1 M Na2SO4

For preparing an ultrathin two-dimensional polymer coating adsorbed on passivated iron, a 16-hydroxyhexadecanoate ion HO(CH₂)₁₅CO₂⁻ self-assembled monolayer (SAM) was modified with 1,2-bis(triethoxysilyl)ethane (C₂H₅O)₃Si(CH₂)₂Si(OC₂H₅)₃ and octadecyltriethoxysilane C₁₈H₃₇Si(OC₂H₅)₃. Protection of passivated iron against passive film breakdown and corrosion of iron was investigated by monitoring of the open-circuit potential and repeated polarization measurements in an aerated 0.1 M Na₂SO₄ solution during immersion for many hours. The time required for passive film breakdown of the polymer-coated electrode was markedly higher in this solution than that of the passivated one, indicating protection of the passive film from breakdown by coverage with the polymer coating. The protective efficiencies of the passive film covered with the coating were extremely high, more than 99.9% in 0.1 M Na₂SO₄ before the passive film was broken down, showing prominent cooperative suppression of iron corrosion in the solution by coverage with the passive film and polymer coating. The polymer-coated surface was characterized by contact angle measurement and electron-probe microanalysis (EPMA). Prevention of passive film breakdown and iron corrosion for the polymer-coated electrode healed in 0.1 M NaNO₃ was also examined in 0.1 M Na₂SO₄.     

Anomalous surface morphology of iron generated after anodic dissolution under magnetic fields

The effects of applied magnetic fields on the anodic dissolution of iron in a sulfuric acid solution were studied by potentiodynamic polarization measurements and electrode morphology observations. Uneven anodic dissolution occurs in the presence of magnetic field and the extent of the electrode surface inhomogeneity increases with magnetic flux density. Severely local dissolution at two edge areas of the iron electrode in the presence of magnetic fields is caused by the inhomogeneous distribution of the magnetic flux density at the ferromagnetic iron electrode and the resultant enhancement of the mass transport rate of interfacial film at local areas.     

Corrosion prevention of passivated iron in 0.1 M NaCl by coverage with an ultrathin polymer coating and healing treatment in 0.1 M NaNO3

An ultrathin, ordered and two-dimensional polymer coating was prepared on a passivated iron electrode by modification of 16-hydroxyhexadecanoate ion HO(CH₂)₁₅CO₂⁻ self-assembled monolayer with 1,2-bis(triethoxysilyl)ethane (C₂H₅O)₃Si(CH₂)₂Si(OC₂H₅)₃ and octadecyltriethoxysilane C₁₈H₃₇Si(OC₂H₅)₃. Subsequently, the electrode was healed in 0.1 M NaNO₃. Protection of passivated iron against passive film breakdown and corrosion of iron was examined by monitoring of the open-circuit potential and repeated polarization measurements of the polymer-coated and healed electrode in an aerated 0.1 M NaCl solution during immersion for many hours. Localized corrosion was markedly prevented by coverage with the polymer coating and the healing treatment in 0.1 M NaNO₃. Prominent protection of iron from corrosion in 0.1 M NaCl was observed before the breakdown occurred. The electrode surface covered with the healed passive film and polymer coating was analyzed by contact angle measurement, X-ray photoelectron spectroscopy and electron-probe microanalysis.     

Oxidation of green rust suspensions containing different chromium ion species

The oxidation of hydrosulphate green rust (GR2(SO₄²⁻)) suspension containing different chromium ion species was investigated by X-ray diffraction, X-ray absorption spectroscopy and transmission electron microscopy. The pH, oxidation-reduction potential and amount of dissolved oxygen in aqueous solutions were measured during the reactions. The results show that the addition of Cr(III)₂(SO₄)₃ solution suppresses the transformation of GR2(SO₄²⁻) into iron oxyhydroxides and oxides in aqueous solution, while the addition of Na₂Cr(VI)O₄ solution promotes the transformation of GR2(SO₄²⁻) in which Cr(VI) is reduced to Cr(III); α-FeOOH particles were refined by the addition of the chromium ions.     

Electrochemical study of corrosion inhibition and adsorption behaviour for pure iron by polyacrylamide in H2SO4: Synergistic effect of iodide ions

Corrosion inhibition and adsorption behaviour for pure iron in 0.5 M H₂SO₄ by polyacrylamide (PA) were investigated using electrochemical techniques. The effect of iodide ion additives was also studied. It was found that inhibition efficiency increased with PA concentration. Corrosion inhibition was afforded by adsorption of PA onto the metal following El-Awady kinetic-thermodynamic adsorption isotherm model via chemisorption mechanism. A mixed inhibition mechanism is proposed for the inhibitive effects of PA as revealed by potentiodynamic polarization technique. A synergistic effect was observed between PA and KI as evident from the values of synergism parameter found to be greater than unity.     

使用外源性标记法研究氯高铁血红素在大鼠体内的铁吸收

目的: 使用外源性标记法研究氯高铁血红素在大鼠体内的铁吸收。方法: 以⁵⁸Fe 标记的氯高铁血红素分别以 40 mg/kg 和 2 mg/kg 的剂量灌胃和静脉注射给予大鼠,并在其给药前和给药后系列时间点采样,用电感耦合等离子体质谱仪(ICP-MS)法测定各个时间点⁵⁸Fe的血药浓度,测得的血药浓度通过DAS2.1.1 求算药动学参数。用⁵⁸Fe的绝对生物利用度评价氯高铁血红素在大鼠体内的铁吸收。结果: 源于氯高铁血红素中的⁵⁸Fe在灌胃给药后 1.5 h 吸收达峰,峰浓度为(220±89) μg/L,在此剂量下源于氯高铁血红素中的⁵⁸Fe绝对生物利用度为 0.93%。结论: 外源性标记法可以用于评价氯高铁血红素在大鼠体内的铁吸收,源于氯高铁血红素的⁵⁸Fe绝对生物利用度为 0.93%。     

Enhanced activity of an In–Fe2O3/H-ZSM-5 catalyst for NO reduction with methane

Selective reduction of NO by CH₄ on an In–Fe₂O₃/H-ZSM-5 catalyst was investigated in the presence of excess oxygen. Compared with In/H-ZSM-5, the In–Fe₂O₃/H-ZSM-5 catalyst with high Fe₂O₃ contents showed higher activity in a wide range of reaction temperatures. It was found that the addition of Fe₂O₃ yielded a promotion effect on CH₄ activation. The influence of water vapor on NO conversion was also investigated. The activity of the In/H-ZSM-5 catalyst has been found to be strongly inhibited by water vapor, while the In–Fe₂O₃/H-ZSM-5 catalyst remained fairly active in the presence of 3.3% steam.     

Synthesis and evaluation of the inhibitor effect of a new class of triazole compounds

In this work, a new class of triazole molecules, containing heteroatoms such as nitrogen and sulphur, is prepared. The effect of these molecules on the corrosion behaviour of iron was investigated. Electrochemical studies were performed in aerated chloride acid solution (1 M) by potentiodynamic polarisation curves. Surfaces were characterised by scanning electron microscopy.

The recorded electrochemical data showed that the corrosion resistance was greatly enhanced in the presence of inhibitor. The maximal protection efficiency exceeded 94%. The corrosion protection could be explained by the adsorption of inhibitor through the S- or N-atom and formation of a protective layer attached to the metal surface.     

优化浇注料,开发喷补料,提高通铁量

详细介绍了优化主沟浇注料性能的过程和改进方法 ,并对法国拉法吉公司的喷补料技术、材料进行了消化、剖析 ,由此开发出替代进口的国产喷补料 ,进而叙述了主沟浇注料和主沟喷补料在实际使用中对提高通铁量和降低耐火材料单耗产生明显的效果。