Abstract: The concentration distribution of pulverized coal in blowpipe of blast furnace was measured in an isothermal two-phase model by means of a computer measuring system based on infrared transmission. The results show that concentration near the exit of oxygen-coal lance is distributed unsymetrically and that the concentration along the direction of the gas-solid jet is much higher. The concentration distributions in the distance about 2.5 times diameter of blowpipe from the exit of the lance tend to be uniform due to the mixing of gas and solid phase rapidly in blowpipe.
Abstract: Instability of horizontal pneumatic conveying system was recognized through analyzing the wave of solid mass flowrate and pressure fluctuation during transportation of solids. Furthermore, an empirical correlation for critical conveying velocity of fine and medium size particles (ds<0.5mm) under high solids loading (range from 30 to 150) at low gas velocities less than 15m/s was proposed.
Abstract: The magnetic field in electromagnetic casting is investigated by experiment on a cold model of caster and numerical calculation. It is concluded that the coupled Circuit Method is effective for computation of magnetic field in EMC. The distribution of magnetic field is uniform around the ingot, except for corner regions. For two-strand EMC unit, the influence of magnetic field of one caster on another is negligible when distance between two casters exceeds 15cm.
Abstract: The process of extracting niobium with solid oxidizer(Fe3O4) from hot iron (called SOENb for short) produced in Baotou China was advanced. The optinum process parameters were below:The temperature of hot iron is 1 350℃; W(oxidizer burden weight/hot iron weight) is 5%-10%. The thermodynamical action of Si, Mn, C, P, Nb in hot iron under the actual conditions was discussed and the effect of oxidizer burden on the iron temperature was analysed.
Abstract: The slag composition dependence of the dephosphorizing properties of BaO-based slags were studied by chemical equilibrium of phosphorus between slag and stainless liquid steel at 1 773K. The relationships between of phosphate capacity and slag compositions,optical basicity,temperature were obtained.
Abstract: A series of theoretical calculation of data of Na2O-V2O5-H2O and Na2O-Ca2O3-H2O have proved the possibility of precipitating V from V、Ga containing NaOH solution and estimated the temperature and the concentration of alkai (ratio of Na2O mass to H2O mass in solution) ranging <40℃ and 0.3~0.4 respectively.
Abstract: The theory of grain growth inhibition by second phase particles has been reviewed and used as a basis to compare the behaviour of various grain refining additives. Attempts have been made to use silica particles for grain refinement in HSLA steels. The theoretical analysis has indicated that high volume fraction of silica particles can form during the solidification process. Small silica particles have also been obtained by the experiment.
Abstract: The production of desilicated zirconia (ZrO2=88.60%-96.90%) and stabilized zirconia (ZrO2 ≥ 91.54%, MgO ≤ 5.39%) was successfully carried out in a plasma facility of 150kW. Factors, such as temperature, time and charge carbon, which affect the removal of silica from zircon were also studied. The desilicated zirconia can be utilized as the replacement of zirconia being made by chemical purifying method to produce the unchangeable diametric tundish nozzle (75% ZrO2) for the use of continuous casting, according to the preliminary examination by steel works, the main characteristic values of this trial-product can meet the requirements of industrial production.
Abstract: The tundish nozzle clogging samples were taken and analyzed. The clogging causes are understood. Main cause is Al2O3 inclusion and hercynite inclusions stick on the nozzle wall and accumulated. By feeding Φ13.5mm CaSi cored wire, the rate of feeding was 120~130m/min or 0.26~0.86 kg/t. The high melting point inclusions were changed into low melting point complex oxides. There was no longer tundish nozzle clogging observed. The most part inclusions were modified into spherical inclusions and their size was small.
Abstract: Static model of converter to control end carbon and temperature has been developed based on the actual performance of 50t commercial converter. De-C rate equation and temperature increment equation were determined by multiple regression analysis based on the mass and heat balance.
Abstract: The ODF method was applied to investigate the rolling texture develop -ment in steel sheet. The texture was also simulated by the Sachs,Taylor, RC and PC models with {110} <111>ship systems. The theoretical models could reproduce the orientation accumulation around {112} <110>,{111} <110>,<111><112>and {001} <110>.It was shown that the {110} <111>ship is very important deformation mechanism in b.c.c. metals. The rolling deformation process can be described more accurately if the assumptions of all models are considered properly. The continuities of both stress and strain during rolling deformation of steel sheet were also discussed.
Abstract: To improve the surface roughness of CVD diamond films, ion beam milling was used to polish the film. The results of this experiment indicate that the ideal incident angle of ion beam varies with the surface morphology and that high accelaration voltage of ion beam is beneficial to achieving high polishing rate. It was also found that the film exposing (100) facets can be most easily polished to achieve Ra 28 nm surface roughness.
Abstract: The properties and microstructure of Fe73.5Nb3Cu1Si13.5B9 new ultrafine crystalline soft magnetic alloy have been investigated.The results have been shown that the alloy is combined with high relative initial permeability of μ(0.08A·m)=14.8×104. low coercivity of Hc=0.6A/m. high saturation magnetic flux density of B800A·m,=1.22 T under the optimum performance with annealing at 535℃, the optimum values of core loss have reached P5·10k=5.6W/kg, P5·20k=17.4W/kg, P5·50k=80W/kg. P5·100k=270W/kg. The alloy has high effective permeability μ'1 in a considerable wide frequency range. The microstructural analysis under X-ray diffraction was detemined that the main crystalline phase in the alloy is xFe-Si solid solution which has ultrafine grain size of d=1 1nm. lattice parameter of a a0=0.2 837nm.
Abstract: In this paper, sheet metal strain-hardening anisotropic parameter X was theortical and experimental investigated. The varying laws and effected factors of X value were explored. The application and interrelation of X value as an index assessing forming ability were analysed and discussed.
Abstract: The experiments for cone bearing and cylinder bearing failures base on real running condition test (not analogue) in a bearing test machine. The vibration and temperature signals are monitored. The signal analysis method, diagnostic parameters choise method,time waveform and spectrum are studied deeply. Many valuable conclusions are obtained and a aood diagnostic is found.
Abstract: Application of pattern recognition and AI is a promisive approach to this problem. In the paper, pattern recognition method is used to test the quality of sinter. On the basis of the algorithm of fuzzy clustering analysis, the classifiers based on fuzzy clustering and dynamic state clustering in microcomputer are set up. The performance of the classifiers is tested. The results show that, in the case of lacking priori knowledge, fuzzy clustering analysis is superior to dynamic state clustering analysis when the number of samples is small.
Abstract: A cyclic vollammelry is emploied to determine the amount of oxide in FLTNAK melt. K2NbF7 is a good litrant. The amount of oxide is also determined by a vollammetric standard addition method. The results show that the amount of oxide in FLINAK melt is equal to the added amount of Nb(V) minus the amount of NbF72- in the melt.
Abstract: An new type of entrained slagging pulverized coal combustor is developed based on cold state model experiment, the velocity distribution and mixing process in the combustor are researched. The results of the experiments show that for the axial velocity distribution, 6 different zones can be found, 4 of which are reverse flow zones. Annular reverse flow zone can be found too in the combustor with the flat-straight slag baffle. The flat-straight slag baffle can replace the cone-convergent one in the design of cyclone combustor. The optimum parameters are that the swirl number of primary air is 1.78 to 2.0, the ratio of primary air is 15% to 20%, the distance between primary air inlet and the secondary one is (0.75-1.15)D.
Abstract: The load distribuion of supporting posts obtained by means of eletrometry combined with theoretical analyses has been studied. The general distribution type has been given. Finally the reason of unbalanced load distribution has bssn analyzed.
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
