Abstract: In accordance with the coexistence theory of slag structure, the structural units of FeO-Fe2O3-SiO2 melts have been determined as simple ions Fe2+, O2- and molecules SiO2, Fe2O3, Fe3O4, Fe2SiO4 as well from the phase diagram and viscosity data of FeOn-SiO2 system and phase diagram of FeOn-Fe2O3. On the basis of these structural units and using the standard free energies of Fe2SiO4 and Fe3O4 formation, calculating model of mass action concentrations for FeO-Fe2O3-SiO2 melts has been deduced. The calculated NFetO are identical with the measured αFetO. The mass action concentrations of NFetO, NSiO2, NFe2SiO4 and the sum of moles Σn change with respect to the basicity ${B_1}=\frac{{\Sigma n{\rm{FeO}}}}{{\Sigma n{\rm{Si}}{{\rm{O}}_2}}}$, but themass action concentrations NFe2O3 and NFe3O4 change with respect to the basicity ${B_2}=\frac{{\Sigma n{\rm{FeO}}}}{{\Sigma n{\rm{F}}{{\rm{e}}_2}{{\rm{O}}_3}}}$, showing that the mixing of Fe2SiO4 and Fe3O4 isideal and their mutual effects are small.
Abstract: This paper discussed the posibility of reduction of molybdenum directly in melt iron, compared the effect of treated method of injection with briquette; made experimental rcsearchs on the effect of alloying for molybdenum on melt iron. It has been found that direct reduction of molybdenum and alloying may be completed simultaneously in industrial melt iron when the temperature is 1300~1550℃.Generally speaking, the injecting method may get better effect than another one.The economical profit will be remarkable when this new technique is successfuly used in the industry.
Abstract: The segregation behaviours of Mg addition in a Ni-Cr-Co base superalloy have been investigated. Both AES and EDS analysis on TEM thin film mold are used for measuring the segregation behaviours of Mg. The results show that the equilibrium segregation of Mg in grain boundaries is taken place; the rate of the Mg segregation to grain boundaries is the fastest near 900℃. These have close interrelation with the segregation kinetics and thermodynamics and the carbides M6C in grain boundaries. In addition, the distribution of Mg in grain boundaries is inhomogeneous, which the increase with increasing of ageing time. Theuresults measured with AES and EDS analysis on TEM thin film mold are similar.
Abstract: In this paper,the regularity of annealing embrittlement for amorphous alloys Fe80B20-xSix (x=6, 8, 10, 12) is studied.The effects of composition,purity of the raw materials, thickness and the surface condition of the ribbons on annealing embrittlement of the alloys are shown.Annealed at lower tmperature,Fe-based amorphous alloys have already become brittle. This annealing embrittlement is caused by structural relaxation which is controlled by the metastability of amorphous alloys.
Abstract: For comprehensive utilization of the rare earth resources in our puntry and to decrease the cost of Nd FeB magnets, the relationshi s between the magnetic properties and composition, processing of the cheap R-Fe-B system permanent magnets have been studied in this paper (R=Pr + Nd, or R=Ce + Pr + Nd). By addition of Al, the coercivity of alloy increases.The optimum magnetic properties of (NdPr)-Fe-B alloy are. Br=1.25T.MHc=714.3kA/m,(BH)m=297.2kJ/m3.The magnetic properties of (PrNd)1-y Cey-Fe-B alloy(y=0~0,5)decrease with increasing Ce content. The magnetic properties are as follows:Br=1.25T, MHc=825.4 kA/m, (BH)m=297.5kJ/m3 for the alloy of y=0.03; Br=1.20T, MHc=563.6kA/m, (BH)m=246kJ/m3 for the alloy of y=0.3, Br=1.13T, MHc=492kA/m, (BH)=222.2kJ/m3 for the alloy of y=0.4; (BH)=174.6kJ/m3 for the alloy of y=0.5. The curie temperature of the alloys is about 609~590K. The reversible temperature coefficient of residual induction is about-0.094~-0.119%/K, The microstructure, density, hardness, specific resistivity of the alloys have been observed and measured respectively.
Abstract: An apparatus for wire drawing with force feed lubrication method was constructed.High pressure region was formed in the neighbourhood of join of the pressure tube and die. The force feed lubrication have many merit in comparison with ordiriary lubrication. It is shown that high pressure region have been existed in pressure tube, and that the pressure have been measured, and that the effect of parameters on pressure of lubrication have been described. This paper by studying an experiment and theory for wire drawing with force feed lubrication is presented that high pressure region is existes in pressure tube, and describes the parameters of having an effect on pressure valu of lubricant.
Abstract: By means of the dense grid moire and the derivation with the third power spline function, the strain rate fields and the stress fields were obtained through a shearing compression experiment. Using the experiment data, the upper and lower surface friction factor functions s were gained. A new model was developed by Nadai's calculation of stres field in a coverging wedge-shape symmetricl channel and was compared with the Others' calculations. It is shown that the results of the new model agree well with those measured in the test.
Abstract: In this work, based oa the literature[1] and[2], the equations of centre line velocity; anypoint velocity in the two phases region of plume, average velocity, recirculatiom flowrate, recirculation circle, mixid time and drawing of the ladel and hydrodynamic model have been derived.
Abstract: First in the paper, a new method has been given to calculate the strain velocity with shear plane machining model. In accordance with the energy consumptions on sawing chip, the formula of the pressure per unit area has been developed, and it has been held that the kinetic energy variation of chip can not be neglected. Using numerical analysis, the shear angle in the above model has been defined. Finally, the method to calculade macroscopic energetics paramefers has been given. Sawing test has defirmed that more satisfactory results can be obtained in analyzing the sawing process with authors, method than others.
Abstract: In this report, the researches on five-rollor straightener have been discussed in detail. The characteristics of the straightener's structure, the methods used for measurements and analysis, are proposed.The results obtained from the measurements and analysis on the straightening forces of the straightener, and the frictionai coefficients between the rollor and the billet under thenormal and high temperature conditions are all introduced. These researches and results will be helpful to the designs of billet caster straightener.
Abstract: This paper aims at improvement of the tension control system of coi-ler of cold tandem mill. We adopt the self-tuning regulator to substitute the original tension regulator. The on-line control has indicated that the application of selftuning regulator on tension control system of coiler is available.
Abstract: In this paper we present the Program System for Computer Aided Rollpass Design of round bar on Computer HITAC M-150 and IBM-PC/XT, The feature and structure of the Program System, each module's function and its realization are discussed in detail. At the same time presents the model for calculating the spread,flowstress,rolling force, moment and rolling temperature.
Abstract: The activities of solid Cu-Al system have been determined at 1000℃ by a concentration galvanic cell employing solid electrolyte in the composition range 0.0234
Abstract: The paper studied the reactions for the formation of subhalides with average valence being less than 2.5 by the reaction of titanium with its liquid tetrachloride at lower temperature 973K in KCl melt. An improved hydrogen evolution method has been developed to determine Ti2+ and Ti3+.
Abstract: The influence of the TiN inclusion on the pitting initiation has been studied. The test results shown that the susceptible sites for pitting initiation of lCr18Ni9Ti in microfield exist around the TiN inclusion. The results by AEM show that the area around the TiN inclusion is lack of Cr,its peak value of Cr/Fe + Ni vs spurttings depth curve is less than that of the site for the TiN inclusion. The sites around TiN inclusion are the valuable area of the passive film. TiN inclusion lower the value of pitting potential in microfield or the ability in pitting resisting.
Abstract: The bright Fe-Cr-P alloy film can be electroplated on the copper with using the amino acetic acid as the complex compound. The result by X-ray diffraction analysis shows that the structure of the film is Bmorphous.The contents of iron,chromium and phosphorus in films are determined by spectrophotometric methods. During the process of electroplating, the change of pH value in solution has drastic influence over the composition of alloy films,The suitable pH value is from 1.2 to 1.8.Raising the operating temperature will reduce the chromium content in alloy films. The cathodic process of the Fe-Cr-P alloy electroplating is under the step of the electrochemical dynamics.
Abstract: A rapid sensitive and selective spectrophotometric method for the determination of total amount of the rare earth elements in the ferroalloy of containing rare earth silicon and magnesium has been developed. A purplish red complex which has ratio of RE to Arsenazo-Ⅲ to be 1:2 can be formed in the range of pH 1.2~2.1 in the ethanol aqueous solution (λmax=648nm,λ648=8.2×104 mol-1cm-1). Beer's law is obeyed in the concentration range of 0 to 50μg/25ml.The interference of Fe(Ⅲ) can be covered with EDTA.
Abstract: In this paper, the method of synthesis and charaterization of pure rhodonite are discussed.At room temperature about 20% by dilute acid, and at about 100℃ more than 50% by dilute hydrochloric acid can be decomposed. It is found by calorimetry that reaction of rhodonite with hydrochloric acid releases the heat to be 85.1±3.6kJ/mol.
Abstract: The effect of water vapour on the thermal decomposition of manganese carbonate was studied with the help of DTA and TG in different atmospheres. The kinetic equations and apparent activation energy for the decomposition reactions of manganese carbonate in dry/wet air and dry/wet 1hydrogen were deduced by the method of non-isothermal kinetics. It has been found that all these processes were diffusion controlled;the apparent activation energy were 173.7, 154.9 and 211.9, 173.7kJ.mol-1 respective-y.According to the experimental results, it believed that the role of water vapour is principally to catalyse the decomposition reaction of manganese carbonate to manganous oxide and carbon dioxide.
Abstract: Tension-torsion biaxial low cycle fatigue tests have been carried ou t on thin-walled tubes with circular holes made from 40 Cr steel. Stress and strain distribution near the circular hole has been analysed with elastic-plastic finite element method. Previous multiaxial fatigue criteria were re-examined. Based on the experimental results and the analysis of thin-walled tuble tension-torsion biaxial fatigue, a new maltiaxial fatigue criterion has been proposed,which predicts both fatigue initiation life and cracking site quite satisfactorily.
Monthly, started in 1955 Supervising institution：Ministry of Education Sponsoring Institution：University of Science and Technology Beijing Editorial office：Editorial Department of Chinese Journal of Engineering Publisher：Science Press Chairperson：Ren-shu Yang Editor-in-Chief：Ai-xiang Wu ISSN 2095-9389CN 2095-9389
