材料期刊网

Model of Calculating Activity of Nitrogen and Vanadium in FeCVN Molten Metal

PENG Jun , WANG Shijun , DONG Yuanchi , LIU Lixia , ZHOU Yun , CHEN Erbao

钢铁研究学报(英文版)

The solubility of nitrogen in the FeCVN system was measured at 1 708 K and the model of calculating activity (action concentration) of nitrogen (N) and vanadium (V) was derived according to the phase diagram and the coexistence theory of the metal melt structure. The solubility expression of nitrogen in the FeCVN system at 1 708 K was wN=0058 194-0010 367wC+0005 543 4wV. Comparing the computing results with the experimental results, a satisfactory conclusion could be obtained. The analysis of the FeCVN system using this model showed that VN was present in a high temperature metal melt, which would reduce the action concentration of nitrogen obviously. It was consequently disadvantageous to the removal of nitrogen from hot metal.

关键词: metal melt;coexistence theory;action concentration;activity

Performance of Low Fluoride Dephosphorization Slag of Hot Metal

LIU Lixia , WANG Shijun , DONG Yuanchi , JIA Xiaohui

钢铁研究学报(英文版)

The purpose of this study is decreasing content of CaF2 in dephosphorization slag. The dephosphorization effects with CaF2 replaced by B2O3 were investigated. The dephosphorization experiments were carried at 1450℃ in air atmosphere. The results show that the melting points and dephosphorization ratios change little when B2O3 replaced CaF2. The dephosphorization ratios which are all greater than 80% and melting points can meet the requirement of hot metal pretreatment. Because of the change of alkalinity caused by B2O3, the oxidation of slag increases with increasing of B2O3 contents. It is beneficial to pre-dephosphorization. As a result, for decreasing its pollution, CaF2 can be replaced by B2O3 to dispose fluoride-free pre-dephosphorization slag.

关键词: Low Fluoride Slag;Hot Metal Pretreatment;Dephosphorization;Phosphate capacity

Thermodynamic Properties of FeCN and FeCBN Melts

CHEN Erbao , WANG Shijun , DONG Yuanchi , WU Baoguo , ZHOU Yun

钢铁研究学报(英文版)

The saturated solubility of carbon and nitrogen in FeCN and FeCBN melts was measured experimentally at 1 485 ℃ to obtain the activity interaction coefficients between components in these melts. A new method was used to treat experimental results. Using thermodynamic derivation and calculation, some important interaction coefficients between components in these melts were obtained.

关键词: FeCN melt;FeCBN melt;FeCB melt;interaction coefficient;thermodynamic property

Studies of the anion position parameter chi of the ternary semiconductor CuGaS2 by use of Ni+ ion probe

Materials Science and Engineering B-Solid State Materials for Advanced Technology

The anion position parameter chi of NiS4 cluster formed in the ternary semiconductor CuGaS2 by substitution of Ni+ for Cu+ has been determined by studying the optical spectra and EPR data for CuGaS2:Ni+. The result (chi approximate to 0.263(1)) is consistent with the mean value of the X-ray measurement results reported in two groups of references and also with the calculated value obtained from the conservation of tetrahedral bonds (CTB) plus eta = eta(tet) rule (where eta = c/2a). So, we suggest that the anion position parameter chi in pure CuGaS2 crystal is close to the above value obtained by use of Ni+ ion probe. The optical absorption bands and g factors g(parallel to), g(perpendicular to), of CuGaS2: Ni+ are therefore explained reasonably from the anion position parameter. (C) 2003 Elsevier B.V. All rights reserved.

关键词: structural parameter;electron paramagnetic resonance (EPR);optical;spectrum crystal-field theory;CuGaS2;Ni+;chalcopyrite semiconductors;superposition model;crystal

Ab initio study of the intrinsic exchange bias at the SrRuO(3)/SrMnO(3) interface

Physical Review B

In a recent publication [S. Dong et al., Phys. Rev. Lett. 103, 127201 (2009)], two (related) mechanisms were proposed to understand the intrinsic exchange bias present in oxides heterostructures involving G-type antiferromagnetic perovskites. The first mechanism is driven by the Dzyaloshinskii-Moriya interaction, which is a spin-orbit coupling effect. The second is induced by the ferroelectric polarization, and it is only active in heterostructures involving multiferroics. Using the SrRuO(3)/SrMnO(3) superlattice as a model system, density-functional calculations are here performed to verify the two proposals. This proof-of-principle calculation provides convincing evidence that qualitatively supports both proposals.

关键词: thin-films;weak ferromagnetism;superlattices;anisotropy;bifeo3;srruo3;model

Influences of variations of characteristic parameters of protein molecules on states of soliton transported bio-energy

International Journal of Modern Physics B

We simulate numerically the dynamic properties of new soliton with quasi-coherent two quanta in the improved model by fourth-order Runge-Kutta way. We observed that the window of formation of new soliton is shifted toward smaller values of coupling constants when compared with the Davydov's soliton with one quantum and Forner's soliton with two quantum model. The new soliton formation starts at (chi 1 + chi 2) = 20 PN, and pinning starts from (chi 1 + chi 2) = 86 PN. The pinned solitons are also observed if both quanta are on the same end of the chain in the initial state. The behaviors of new soliton are varied under influences for variations of characteristic parameters arising from the structure nonuniformity of protein molecules. Although the new soliton is also sensitive to the dipole-dipole interaction and diagonal disorder, the sensitivity to the impurity is weaker than that of the Davydov's and Forner's solitons. Therefore, the new soliton is robust against the fluctuations of coupled constant, dipole-dipole interaction and diagonal disorder arising from the impurity or structure nonuniformity, when compared with that of the Davydov's and Forner's solitons.

关键词: protein;bio-energy transport;soliton;structure nonuniformity;characteristic parameter;davydov soliton;living systems;improved model;thermodynamic;properties;biological temperature;finite-temperature;quantum;dynamics;disorder;lifetime

Effects of Mo on the Precipitation Behaviors in High-Nitrogen Austenitic Stainless Steels

Feng Shi

材料科学技术（英文）

Precipitation behaviors of Fe-18Cr-18Mn-0.63N and Fe-18Cr-18Mn-2Mo-0.69N high-nitrogen austenitic stainless steels during isothermally aging at 850°C have been investigated by optical microscopy (OM), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and X-ray diffraction (XRD). The experimental results show that precipitation displays a discontinuous cellular way and the precipitates are identified as Cr₂N in Fe-18Cr-18Mn-0.63N steel. The addition of Mo makes precipitation occur not only at the grain boundary but also inside the grain and precipitation also displays discontinuous cellular way. The precipitates at the grain boundary and in the cell are both identified as Cr₂N phase and χ phase and the precipitates inside the grain are identified as Χ phase in Fe-18Cr-18Mn-2Mo-0.69N steel. The nucleations of  Χ phase and Cr₂N phase at the grain boundary are both governed by the diffusion of Cr atoms. The formation and growth of χ phase inside the grain are induced by the impoverishment of N atoms with increasing aging time.

关键词: Austenitic stainless steel

时效温度对铸造超级双相不锈钢析出相的影响

向红亮何福善刘东

金属学报

对固溶处理后的铸造超级双相不锈钢材料进行时效处理, 利用OM, SEM, XRD和TEM分析了时效温度对析出相的影响. 结果表明, 固溶后经时效处理, 金属间相在铁素体内和铁素体/奥氏体晶界析出; 650℃时效时, 析出的金属间相主要是χ相; 750℃时效时析出σ相和χ相, 此时σ相由χ相演变而来; 850℃时效下则直接析出σ相; 950℃时效后, 少量的σ相仅在铁素体/奥氏体晶界产生.

关键词: 铸造超级双相不锈钢 , aging temperatures , σ phase , χ phase

Intensified alkaline leaching pretreatment of refractory gold concentrates at common temperature and pressure

Transactions of Nonferrous Metals Society of China

A new process for the hydrometallurgy of refractory gold concentrates was presented. The process comprises grinding-leaching, intensified alkaline leaching (IAL), cyanidation and adsorption. In a stirring-type pulverizing-leaching tower mill, the concentrate is ground to <35. 6 μm of 95. 5 % while simultaneously leached by NaOH of 12 kg/t, then carried out intensified alkaline leaching for 48 h by NaOH of 108 kg/t in enhanced agitation tanks with the pulp concentration of 40% solids at the environmental temperature of 9. 5 &SIM; 13. 5 &DEG;C and the environmental pressure of 10(5) Pa. The oxidation rate of As is 94. 9%, and 47. 6% for S. The total consumption of NaOH is only 20% of that theoretically calculated under the conditions of full oxidation at the same oxidation rates of arsenic to arsenate and sulfur to sulfate. The gold leaching rate by NaCN in 24 h is increased from 9. 2% before pretreatment to 94. 2%. The consumption of NaCN is 7. 5 kg/t, which is one times less than that before pretreatment. The extraction cost of gold is about 422 Yuan/t.

关键词: refractory gold concentrates;grinding-leaching;intensified alkaline;leaching (IAL);pretreatment;common temperature and pressure

冷却速率对GWZ1032K合金中14H-LPSO结构形成的影响

张松袁广银卢晨丁文江

金属学报 doi:10.3724/SP.J.1037.2010.00177

采用金属型铸造和慢速凝固, 在不同冷却速率下制备了Mg-10Gd-3Y-1.8Zn-0.5Zr(质量分数, %) (GWZ1032K)合金. 采用SEM, TEM和XRD研究了冷却速率不同的GWZ1032K 合金的组织和相构成. 在GWZ1032K合金中, α-Mg基体中的层片状14H-LPSO结构随着冷却速率的下降而增加, 在冷却速率为0.005℃/s的试样中充满了整个晶粒;随着合金冷却速率降低, GWZ1032K合金中晶界第二相分别由5℃/s时的(Mg, Zn)₃RE相转变为0.5 和0.1℃/s时的(Mg, Zn)₃RE相和14H-LPSO结构的&chi;相共存;在0.01和0.005℃/s时只有14H-LPSO结构的$\chi$相. 结果显示在接近于平衡凝固的缓慢冷速条件下, 更容易形成具有稳定结构的层片状14H-LPSO结构和&chi;相.在冷却速率为0.5和0.1℃/s时, (Mg, Zn)₃RE共晶相和&chi;相共存, (Mg, Zn)₃RE共晶相和&chi;相的位向关系为 [110]_{&chi; phase}//[223]_{(Mg, Zn)3RE}和∠g(001)_{&chi; phase} g(110) _{(Mg, Zn)3RE}=8.4°.

关键词: 14H-LPSO结构 , solidification rate , Mg-Gd-Y-Zn alloy , &chi; phase