Abstract: Through the analysis with ESCA charts, it has proved that BET on the surface of Coal is absorbed by adding the BET as the increasing. The BET is not adsorbed basically on the surface of pyrite. The major difference between coal-pyrite and mineral-pyrite lies in their respective carbon spectroscopes. The peak intensity of coal-pyrite is obviously greater than that of mineral-pyrite. As seen in the form of the peaks, the irregularity of coal-pyrite is greater, showing that the existing form of carbonic materials in coal-pyrite is complex; whereas the carbon in mineral-pyrite exists mainly in the form of impurity carbon, and its surface content is about 30%. In terms of chemical computation composition, in minerals with carbon, its surface carbon content is more than 40%. There is no doubt that a high content of carbon plays a great part in the floatation of coal-pyrite. As a matter of fact, the carbonic pollution in the surface of pyrite and the incomplete isolation of coal and pyrite are one of the major reasons that coal and pyrite are hard to separate from each other. Through ultrasonic treatment, the absorption of Ca2+ on the surface of pyrite is further enhanced, and the Ca content increases form 0.95% to 2.95%. This proves that the desulfuration and deashing of coal through ultrasonic treatment is to enhance the absorption of Ca(OH)2 on the surface of pyrite, and eventually to further depress pyrite.
Abstract: Based on the analysis and research on a controlled object characteristic for coal preparation with air-dense medium fluidized bed, a inverse-controlled method is put forward to solve the density and height control for the fluidized bed. A mathematical model is established. The inverse system control method is introduced, and the results show a high control precision.
Abstract: The commercial code CFX4.3 was applied to simulate fluid flow in the mold of No.l continuous slab-casting machine in BaoSteel. The simulated velocity vector at the nozzle outlet ports was used as inlet boundary conditions of the mold. Results indicated that the velocity vector was not evenly distributed at the nozzle outlets and its direction may not be consistent with the ports. For this reason, it was necessary to connect the nozzle simulation results with the mold model to better reflect the real flow field.
Abstract: Based on thermodynamic calculations, the simulating tests on dephosphurization of stainless steel were carried out. The key points of the De-P process were analyzed. It is suggested that the [C] be kept above 1.55% in the De-P process.
Abstract: The phenomenon of DC arc was studied. Through the analysis of arc transmisson and I/O power for DC Arc Furnace, the DC passageway model was set up. This model provides a theoretic basis to control DC arc and correct the arc direction.
Abstract: The effect of controlled rolling and cooling process parameters on the precipitated pearlite of 60Si2MnA spring steel wire rods is carefully investigated. Experimental results show that when other process parameters are alike, the interlamellar pearlite spacing of 60Si2MnA wire rods is mainly determined by cooling rate in the process from the rod layer to the coil collecting station. The more rapid the cooling rate in this process, the thinner the interlamellar pearlite spacing. The interlamellar pearlite spacing tends to reduce with the increase of finishing temperature or rod-laying temperature. The degenerative pearlite emerges especially after cooling at a rapid rate and its content increases with the elevation of cooling rate after finish rolling. The pearlite colony becomes small obviously at a low finishing temperature.
Abstract: Precipitation effects on austenite recrystallization were studied with Gleeble 1500 in the traditional rolling and the direct hot rolling. The influence of the precipitation of C, N on the microstructure and properties was investigated in the direct rolling of Q245 steel. It can be concluded that the precipition of C,N could fine the austenite grain size and improve the microstrutre and properties of steel.
Abstract: The influence of solid-solution temperature on hardness, grain size and precipitate behavior was investigated in order to obtain the definite range of the solid-solution process. It is shown that the solid-solution temperature has a relatively obvious effect on the hardness, a great effect on the grain size in Inconel690 alloy. When the temperature is over 10701, the grain size increases remarkably. The theoretical computation and SEM show that (Fe,Cr,Ni)23C6 carbide in Inconel690 dissolves completely at temperatures of 1070-1 090 ℃.
Abstract: The microstructure developing of 60Si2Mn semisolid slurry was investigated experimentally with self-made high melting point semisolid apparatus. The results show that the as-received microstructure of semisolid samples presents globular crystals evenly distributed in the liquid phase. Stirring way and stirring power and time have evident effect on the solidifying pattern of the primary phase. The as-received prior microstructure which is stirred in the isothermal way evolve fully finer and rounder with the increase of stirring power and time. The morphology of 60Si2Mn semisolid samples is major factors that affect the shear thinning behavior.
Abstract: The coarsening tendency of ultra-fine ferrite grains produced by deformation-enhanced transformation was investigated at simulated coiling temperatures by thermal simulating tests in four low carbon steels containing different C and Mn contents. Results show that the ultra-fine microstructures are quite stable. No apparent coarsening and static recrystallization of ferrite grains were detected and they are ascribed to the effective pinning by the second/minor phases. The evolution of second phases in four steels was different. During holding at coiling temperatures the transformation of austenite to perlite proceeded in a divorced manner owing to the strong deformation of austenite. Orientation mapping in EBSD measurements was also applied to reveal the changes of (mis)orientations of ferrite grains during holding.
Abstract: A Cu/Al galvanic couple was used to simulate the electrochemical behavior of LY12 aluminum alloy in cerium salt solutions. The galvanic current decreased with time from 0.08 mV to 0.005 mV after immersion in the solutions, which indicates that the corrosion was inhibited. The galvanic potential moved negatively, which shows the cerium film inhibits the cathodic reaction. After 8 h of immersion, a yellow layer was formed on the copper of the galvanic couple. SEM, EDX anslyses show that the layer has a dry mud appearance and contains a mess of Ce.
Abstract: A series of LiNi1-xCoxO2 (0<x< 1) were synthesized by solid state reaction. The effect of Co3+ substitution on Ni3+ content was investigated by XRD and electrochemical techniques. It is shown that LiNi0.8C0.2O2 has the best electrochemical performance, delivering specific capacities of 170-180 mAh/g and good over-charge resistance compared with LiNiO2.
Abstract: During the hot rolling of seamless steel tubes, internal surface folding (ISF) is frequently formed in Baotou Iron & Steel Co. The main factors, which caused the ISF, are analyzed using the method of step regression. Results show that the lower value of [Mn]/[S], the higher casting overheaded level △t and pulling velocity v are the main reasons caused ISF.
Abstract: Workpiece forming in the T-shaped tube hydroforming process takes place through internal pressure and axial load. If these loads are chosen poorly there will be failure in the workpiece involving wrinkle or bursting. A dynamic FEM model is built for the T-shaped tube hydroforming process. Through analyzing the different simulation results, the influence of axial load is discussed and the optimum loading profile is determined.
Abstract: A flatness model expressed by the difference of entrance strip crown and exit strip crown is built based on the definition of flatness and the invariable cubage theory of strip rolling, and the entrance strip shape is also considered in the flatness model. The model was used in the rolling parameters optimal design system and the rolling shape optimal design system, and good results were obtained.
Abstract: A mathematic control model used in the accelerated cooling process is presented according to the characteristic of the first set of high-denseness pipe laminar flow accelerated cooling device in China which is built in the Heavy Plate Mill of Anshan Iron and Steel Co. The model consists of the cooling process setting model, the temperature forecast model and the temperature modifying and adapting model. A satisfactory precision has been obtained since it was used.
Abstract: The present accuracy level of the temperature model and the relation between the setup accuracy and influence factors are researched beginning with actual production data. Source codes about the original temperature model are interpreted and then transplanted to PC. Through a lot of off-line statistics and regression analysis, an effective solution is propsed for improving the temperature model. The Idea of this solution can be suitable to other hot rolling product lines.
Abstract: A new method for optimizing the scheduling of cold continuous rolling mills is proposed by means of the Immune Genetic Algorithm and BP networks. The method has many advantages such as stonger learning function, higher computational accuracy, and being convenient for use and suitable for on-line calculation. With a example, the effectiveness of the method is proved.
Abstract: A intelligent coordination control of the multi-stand tandem and multi-function AGC arithmetic is introduced. The AGC parameters self-tunning and the monitor AGC fuzzy control method are proposed. The effectiveness of actual applications as also presented.
Abstract: Strip rolling is a very complicated nonlinear process, and flatness control (AFC) and gauge control (AGC) are a decoupled complex system. A kind of strip flatness and gauge complex control system is presented based on the fuzzy RBF neural network (FRBF) multivariable controller design method. Simulation results show that this kind of new controller has good performances of adaptively tracking target and resisting disturbances and is superior to the conventional decoupled PID control in terms of improving the strip flatness and gauge accuracy.
Abstract: In order to perform the function of automatic backup of the OPTO22 control system, a series of problems, including the linking between the main and backup controllers, their data exchange, recognition of system failure and their automatic interchange, must be resolved. A solution scheme is put forward based on problems in practice.
Abstract: Based on the structural analyse of the steel ball rollers of skew rolling, the profile data of parts such as type, basic figure, manufacturing feature and size was extracted from the 3-dimention model in the ARX exploiting circumstance using MCAD API, the developing tools of MDT. The manufacturing feature data was extracted according to the corresponding 2-dimention drawings. At last, parts information was put in order and recognized automatically on the basis of the relations between the model and drawings. A extracting information system for the rollers was developed, directly from the CAD system then turned it into the CAPP system in the CAD/CAPP/CAM integrated circumstance. The method can be used in extracting the information of general rolling parts also.
Abstract: An effective data compression technique, the principal element analysis method, is proposed to tackle the short-comings of human influences and redundancy during data dimension reductions in the pattern recognition. It shows the advantages of high speed, good accuracy, and automatic completion. The effective rate reaches 85.18%.
Abstract: The defect in the knowledge bases of the traditional expert systems is briefly discussed and then an atmospheric corrosive knowledge base of carbon steel and low alloy steel based on artificial neural networks is presented. The knowledge acquisition, knowledge representation and system fulfillment in this new knowledge base system are described in detail.
Abstract: A novel type of 3 radiation ionization gas flowmeter is introduced based on the molecule-marked method measuring the air stream velocity. The faint current from a ionization room is detected to a computer through an A/D converter after being magnified and filtered by an analogue-signal-processing circuit. Through a peak-seeking software, the flow rate can be achieved by the non-touching method even under bad conditions. The detailed design of hardware and software is given.
Abstract: The Iterated Function System (IPS) is an important theoretic and applied branch of fractal geometry. An IPS defines a point set called the attractor, but there have not any effective methods to obtain the corresponding IPS of a given point set. This paper first proposes an approach to constructing a function for a finite point set defined on the one-dimensional line, so the problem of determining the coefficinets of the affine transformation in an IPS is transfered into determining the extreme points of a the function. This method is then, extended to the two-dimesional plane.
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
