Abstract: A new direct mensuration method of dust granularity distribution with Masyersier X dispersive degree instrument is put forward. This method was implemented by gathering data in many spot once with sticking-dust agent, polyhedron empty ball and CH2Cl2. Dust concentration and granularity of mine laneway were determined. Dust distribution condition of a intake cross-section in Zhang Chun mine was analyzed.
Abstract: The reduction experiment of the pellets containing carbon, which consist of different kinds of iron ore and coal (including graphite and charcoal), was carbon out. The effect of temperature, rate of carbon and volatility etc. on the reduction time and metallization of the pellets has been discussed. The strength of the reduced and cooled pellets was measured and the influence of the factors was analysed. The strength of pellets at temperature 1273 K is low. When the gas coal of high volatility is added, the pellet is becoming to be reduced quickly and its strength is increased.
Abstract: The polystyrene canon exchange resin were exchanged byNi2+ ions and then were carbonized to make resin carbon. The elements and structure of the resin carbon were analyzed, and the electrochemical properties of the resin carbon as the electrode of the lithium ion cell were also investigated. The test shown that the element contents of the hydrogen and oxygen were increased and the one of the sulpher was fall for the resin carbon material derived fromNi2+ ion adulterating polystyrene canon exchange resin to compare with the one from the noNi2+ ion adulterating resin. The test also found that it is to increase the graphite degree of the resin carbon, to accelerate the bigger stratum graphite minicrystal structure to form, as well as to be prone to array in the uprightness direction of the strata graphite minicrystal for theNi2+ ion adulterating resin. The electrochemical test also proved that the lithium ion cell, was assembled by the resin carbon derived fromNi2+ ion adulterating resin, had much better electrochemical property than the one from noNi2+ ion adulterating resin, and the capacity of the charge and discharge of the cell was increased about 20 (mA·h)/g in average, at one time, the first charge and discharge irreversibility of the lithium ion cell was fall evidently.
Abstract: Based on morphology, it is presented that morphotype conversion of foams in metallurgical melts would occur during foam evolution, which has been proved by experimental results. By means of morphotype conversion, a new interpretation on foams decay process was provided for promotion of kinetics on foaming. Characteristic numbers Ga and factor Sa were employed to be as criterion to qualitatively determine the decay rate before and after the morphotype conversion, respectively. The reasons also were given on contrast in foams stability from different liquid and gas source.
Abstract: Austenitic stainless steel composite strips 302/C1 015 were made by using inversion casting method in laboratorial experiments. It was observed in metallographic examination and SEM investigation that the composite strips consisted of three different parts each with different microstructures, i. e. the zone of mother sheet of carbon steel, newly crystallized layers of austenitic stainless steel and transition area between mother sheet and the newly solidified layer. The results of shearing test on the composite strip show that the interfacial shearing intensity can meet the demands of national criterion.
Abstract: Calculating and analyzing the gas reforming result of smelting reduction process by modeling method. The relationship of the gases composition and temperature before and after reforming is obtained. It shows that the energy consumption in smelting reduction process will reduced by this way and the best condition is gas reforming at self-balance operation area.
Abstract: A process route comprising air induction melting (AIM) and electroslag remelting (ESR) for Production of Fe3Al based containing Cr alloys has been developed. The effect of melting practice on the purity of elements,inclusions and properties is reported. Proper selection and control of Power input during electroslag remelting resulted in clean, sound,homogenous and defect-free ingots. The content of S,O, H,P in the samples were decreased, and the size and distribution of inclusion were changed. After hot forging and thermomechanical process, the longitudinal elongation at room temperature is over 8% and 10% for two kinds of materials, yield strength is over 400 MPa, and ultimate tensile Strength is about 700 MPa. It is more possible to melt Fe3Al based alloys by ESR.
Abstract: Deforming physical field of inversely casting austenitic stainless steel strip during level rolling process was analyzed by ANSYS program. Plastic strain and stress of all the nodes were gained, which shows:There exists uneven deformation in the strip. Strain of the mother sheet is larger than that of the growth layer. Strain of the growth layer becomes larger from surface to inside. In the deformational zone, the stress of the growth layer is larger than that of the mother sheet. The residual stress in the strip is about 19 MPa. The rolling force estimated with ANSYS program is corresponded to those measured.
Abstract: With the finite element analysis system ANSYS, the temperature field in blast furnace wall, cooled with flanged stave system, was numerically simulated. The influence of the refractory kind and its wear extend was' investigated, and the principal reason and process of wear of the blast furnace lower shaft wall was discussed. Analytical results show that the insufficient cooling capability of the stave flanged part results in the maximum temperature on the lining hot face is always higher than its chemical erosion critical temperature, and no equilibrium thickness lining could be kept steadily on the front of flanged part of the stave.
Abstract: Throughout studying the relationship between the compact density and the compacting pressure the compacting temperature, tasting the microhardness of particles in the compact, detecting the distribution oflubricant in the compact, the densification mechanism of warm compaction can be concluded as following:the compaction principle of iron powder is the same as that of conventional compaction. while the effective pressure during warm compaction is larger than that of conventional compaction. The temperature during compaction can slow down the progress of work hardness and improve the plasticity of iron powder. The lubricant is only effective at the optimum temperature. Under this condition, the lubrication takes place of viscous flow, which can be squeezed oat of the compact, effectively reducing the friction between particles and between particle and die wall, and also decreasing the ejection pressure.
Abstract: The influence of electromagnetic stirring on the solidification structures of the spring steel castings or ingots has been investigated. The experiments have shown that the large columnar dendric austenitie formed in a conventional unstirred castings can be substituted by fine equiaxed grains or dedendric grains when stirred with electromagnetic field for a short time. The higher stirring power, the more spherical or dedendritic the austenite was obtained. The amount of austenite nucleation increased and austenite grain become finer in stirring castings.
Abstract: The synergy of corrosion and wear in the fretting corrosion of ICrl3 stainless steel in NaCl solution was studied by means of the fretting corrosion measuring and testing system. In the experiments, it would be found that cathodic protection can not completely inhibit corrosion of ICrl3 in 3.5%NaCl solution. Liquid lubrication effect on weight loss is contrary to synergetic effect, so lubrication effect should be differentiated from synergetic effect. A new mathematical model was presented to qualitatively estimate synergetic effect of corrosion and wear.
Abstract: Four types of B.C coatings (one is B4C non-FGM coating and others are B4C/Cu FGM coatings with the composition distribution factor p=0.2, 1, 2) were fabricated by atmosphere plasma spray on copper substrates. The microstructure of B4C/Cu FGM coatings was observed by SEM. The residual Stress was analyzed by XRD. The thermal cycling behavior for both non-FGM coating and FGM coating was investigated. B4C/Cu FGM coating with p=l shows better thermal shock resistance comparing with that of non-FGM coating and other B4C/Cu FGM coatings. The chemical sputtering performance of B4C coating was also tested.
Abstract: Atmospheric corrosion rates of carbon steel and low alloy steel were Predicted by using different models:two regressive models (D=ATn,D=ATBeC/T), GM(l, l) model of "Gray system", and synthetic factors model of atmospheric corrosion. By comparing the calculated values with exposed test values, it indicated that same materials have different corrosion rules in different environments at the same time for different materials have different prediction models in the same environment.
Abstract: The sintering behavior of tungsten heavy alloys with high Ni/Fe ratios was investigated. The results show that under the same sintering conditions, the sintered densities of the alloys and the growth rate of the tungsten grains increase with the increase of the Ni/Fe ratio. The tungsten heavy alloys with low Ni/Fe ratios are difficult to be densified by the circular sintering process. For the alloys with high Ni/Fe ratios, however, the circular sintering is a effective process to obtain a high density sintered and restrain the growth of tungsten grains during sintering.
Abstract: The distribution of the thermal stress of large area diamond films is given by applying the actual boundary condition, and it is checked by experiments. The result is that the thermal stress of large area diamond films is not uniform, the thermal stress in the middle of large area diamond films is lager than that in the edge of large area diamond films, the press stress is the mainly part of the thermal stress. The crack of diamond films is mainly duo to the large press stress.
Abstract: Numerical model for large area diamond film deposition by DC Arc Plasma Jet CVD method is proposed. Chemical environment over the substrate surface during diamond growth were calculated, and was compared with experiment data from optical emission spectrum obtained at similar conditions. It was found that the CH radical may be main active precursor responsible for diamond growth. The overall uniform distribution of CH radical is important for large area deposition of diamond films.
Abstract: The carbon nitride thin films have been prepared on Si substrates, using N,/CH. as reactive gases, by microwave chemical vapor deposition method. The effect of substrate temperature on the composition and structure of carbon nitride thin films were studied by X-ray photoelectron spectroscopy (XPS). As the substrate temperature increased, the N/C atomic ratios increased rapidly first and then decreased a little after a crucial temperature. Fourier transform infrared (FT-IR) and Raman spectra support the existence of C-N covalent bond.
Abstract: PVA-hydrogel is attached to the metal fibre mesh by means of micro-mechanical interlock method at first, then the surface of metal fibre mesh is bonded to the underlying bone by the bone cement (PMMA). In this way, the artificial cartilage can be firmly attached to the underlying bone (or metal substrate). Microstructure analysis and mechanical tests show that the attachment between artificial cartilage and the metal substrate is firm.
Abstract: The x=0.2,0.4,0.6,80 layers of (l -x) (80%B4C-20%SiC)/xC (volume fraction) Functionally Graded Materials were hot-pressed respectively. The density, linear thermal expansion, elastic modulus and flexural strength were tested. There are crackles in FGMs of 6 and 11 layers that are designed by linear function. The S-type function of compositional distribution as a designed method applied to investigate FGM. As a result the flexural strength is 216 MPa and thermal shock resistance Δfc>500℃ for 11 layers (x=0.2~l) FGMs of S-type.
Abstract: Strain induced ferrite in a coarse austenite grain Q235 steel was investigated in detail by analyzing samples subjected to different strains. Results revel that the strain induced ferrite formed was influenced by the size ofaustenite grain. Ferrite nucleated on grain boundaries, annealing twin boundaries in large y grained sample at the early stage of deformation and upon further straining on deformation bands. Whereas, ferrite nucleates mainly on grain boundaries in small Y grained samples being insensitive to strain scale. With the increase of y grain size, nucleation on the deformation bands was apparently increased and with respect to that on grain boundaries.
Abstract: An in-depth study has been made on the hydraulic roll-bending device, which is widely used in modem cold tandem mill to regulate strip flatness. Based on analyzing the relationship of some factors associated with roll-bending force such as roll profile, strip width and rolling force etc with roll-bending force, an automatic bending-force setting model for cold tandem rolling mill was developed. The model has been successfully applied to two largest cold tandem mills in China and the experimental data proved that the model is reasonable and effective.
Abstract: The main advanced shape control technologies in operation now were studied and compared, for this reason, shape-adjusting action matrices and mills' overall shape control performances of these actuators were imitated by numerical calculation methods. The research conclusions will be not only beneficial to design of strip rolling mills and selection of shape control actuators for a mill, but also beneficial to creating new advanced shape control technologies.
Abstract: It is the first time to propose the application of wavelet decomposition to non-stationary time series forecasting. Non-stationary time series can be decomposed into several pseudo-stationary time series with wavelet decomposition. Each pseudo-stationary time series is forecasted with AR(n) modal to get the final result of forecasting. The method is used in forecasting wear trend of a beating pedestal in a compressor driving. system. Compared with Back-propagation network based method, the method obtains far more Precise results with shorter time, and can be applied to forecasting of machine running condition and analysis of machine fault trend effectively.
Abstract: An image compression method with Visual Entropy-Based segmentation is presented. Firstly the induction of the characteristics of Human Vision System(HVS) and the principles for Visual Entropy-based segmentation is made. Then the mathematic definition for quantification of image character and the algorithm for Visual Entropy-Based segmentation are fully described. The experimental results have shown that image compression with Visual Entropy-Based segmentation can not only gets a rather low bit rate but also gives satisfactory subjective perceptual quality. This method has well emulated the properties of HVS.
Abstract: The multistep predictive modeling of MIMO nonlinear system based on multilayer local recurrent neural networks is presented. The predictive outputs and Jocobian matrixs of output vecter versus input vecter are proffered by the neural networks predictive model for the multistep predictive control systems. The results of simulation show that predictive model of the dynamic neural networks can reach higher degree of accuracy.
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
