Abstract: The isothermal adsorbing experiment of coal collected in different areas and coal basins with different metamorphose degrees was synthetically analyzed. It is indicated that the adsorbing capability of coal relates to many factors including the metamorphose degree of coal, temperature and pressure of the coal-bed methane-stored layer, and moisture type and content of coal etc. This experimental result was verified in practice.
Abstract: The influence of underground water on the stability of joint slopes was studied completely by the synthetic method of qualitative and quantitative analyses. First, a numerical simulation of underground water flowing in a slope was made by the dispersed element method. Then, an uncertain method-fuzzy point estimation was used to analyse the reliability of the slope under the conditions of water ignored and considered, respectively. The results showed that the failure area extended, the failure probability increased greatly, and the reliability index decreased greatly when water was considered. It is concluded that water has unignored effect on slope stability.
Abstract: The neural network structural computation method was applied to the trend statistics and prediction of stress evolvement in the large scale mine-out area supported by rock-based composite materials. The predicting values were compared with the in-situ monitoring ones. The results show they are very agreeable.
Abstract: Based on the fuzzy control theory, a fuzzy controller was designed to change the damp and stiffness of a subordinate tuned mass damper and to achieve fuzzy control of a semi-active tuned mass damper (SATMD). Numerical simulation analyses indicated that the method improved the performance of earthquake control of a passive tuned mass damper effectively.
Abstract: The effect of various process factors for producing tire cord steel on inclusion composition was discussed by thermodynamic calculations. Some advice was proposed for controlling inclusion composition, which includes deoxidization with the Si-Mn alloy without aluminum, dissolved aluminum controlled within 1×10-6~5×10-6 in mass fraction, using ladle lining without alumina, creasing vacuum degree over 300 Pa and canceling feed Si-Ca line.
Abstract: A type of non-leaded free cutting steel was developed by adding tin into steel melt. Machining tests and mechanical tests of the steel were conducted. The results showed that tin would improve the machinability of the steel when the tin content in the steel was less than 0.05%, and any negative influence was not found on the mechanical properties of the steel.
Abstract: The pin shooting and the heat transfer model were used to measure the liquid core length of continuously cast slabs. The results show that these two methods accord with each other very well. It is concluded that the pin shooting is an effective way and worthy of being recommended for its accuracy and low cost.
Abstract: In order to achieve high efficiency, energy saving and low contamination emission for a reheating furnace with the high-temperature low-oxygen combustion technology, a regenerative combustion system of the furnace was designed by the way of numerical simulation, and a set of patent technologies was developed by the theory of metallurgical reaction engineering. An applied result of the patent technologies in Tanggang High-Speed Wire Mill indicated that the energy consume is 0.879 GJ/t, the thermal efficiency of the furnace exceeds 67%, the temperature of emission exhaust gas from the regenerator is below 160℃, and the NOx content in exhaust gas is less than 40×10-6 in voluminal fraction.
Abstract: The mass flow simulation system of thin slab continuous casting and rolling process in Tangshan iron and steel company was developed by integrating the technologies of simulation, database, network, communication and computer. This system is composed of six subsystems:scheduling, steelmaking, refining, continuous casting, reheating and continuous rolling. The main work of the scheduling subsystem are:initializing simulation parameters, establishing produce schedule and real modifying. The main work of other subsystems are procedure simulating, parameters enacting and malfunction arising. This software can simulate the producing process so as to realize the reasonable joining and matching of all the procedures in the producing line. The scheduling plan can be established and modified on-line according to the real production conditions. The malfunctions can be disposed timely and flexibly.
Abstract: The carbide composition, quantity and particle size distribution of HSLC steel produced by CSP process were studied by chemical phase analysis and SAXS method with a 3014 X-ray diffracto-spectrometer and a Kratky small angle scattering goniometer. It is found that the content of carbide with its size less than 18 nm is more than that of Nb(CxNy) with its size less than 18 nm in Nb-contained CSP-HSLA steel reported in reference. The strengthening effect of nano-scale carbide on the steel was discussed.
Abstract: The TiC/Ti-5Mo-5V-2Cr-3Al composites formed by melt in-situ spray forming were fabricated. The tensile properties of the composites were tested, and the way of further improving the strength of TiC/Ti-5Mo-5V-2Cr-3Al composites was also discussed.
Abstract: The grain growth behavior of melt in-situ reaction spray deposited 7075+TiC (2.91%, voluminal fraction) alloy were studied, and the effect of in-situ TiC particles on the microstructure of spray-formed 7075 alloy was investigated. The sectioned specimens were heat-treated isothermally at various temperatures between the solidus and liquidus of 7075 alloy for times in the range of 10-60 min, then quenched in water. The microstructure of reheated specimens was characterized using SEM and the grain size was measured using a mean linear intercept method. It is shown that the in-situ TiC particles can effectively control grain size even at 600℃ after 60 min.
Abstract: The effect of electro-magnetic stirring process parameters on the microstructure of semi-solid AZ91D alloy was studied. The results showed that the shape of solid particles in the alloy was rosette-like or granular. With the stirring power increasing, the rosette-like particles disappeared gradually, and solid particles got more and more spherical. A higher power made the solid particles of the alloy more spherical, because the main evolution mechanism of microstructure of the alloy was the dendritic arm melting method. A higher frequency introduced a skin effect on the stirred semi-solid slurry, which made a temperature difference between the edge and the center. The slurry under electro-magnetic stirring took a secondary flow besides the horizontal rotating flow, which made the slurry move from the edge to the center in cycles. This secondary flow resulted in a promotion of dendritic arm being melted away from the dendrite grains by the large temperature fluctuation.
Abstract: TiSiW12O40/TiO2 was used as catalyst for the esterification of propionic acid with ethanol, propanol, butanol, n-amyl alcohol and iso-amyl alcohol. The effects of the molar ratio of alcohol to propionic acid, the amount of the catalyst, and the reaction time on synthesizing propionates were investigated. A suitable condition for synthesizing propionates was obtained, that is, the molar ratio of alcohol to propionic acid is 1.3:1, the mass ratio of the catalyst used to the reactants 2.0%, and the reaction time 1.0 h. Under this condition, the yield of ethyl propionate is 50.3%, n-propyl propionate 71.4%, n-butyl propionate 93.0%, n-amyl propionate 96.7% and iso-amyl propionate 76.2%.
Abstract: With a geometrical model of porous materials, 3D finite-element analysis on the rolling process of 60Si2Mn in the semi-solid state was carried out using the software MARC. In terms of flat and groove rolling conditions, the stress field and strain field were studied. During groove rolling, the distributions of stress and strain on the cross-section of the deformation zone was more uniform than those during flat rolling. Simulation results were good agreement with experiment data, and showed that semi-solid material was suitable for groove rolling.
Abstract: The tension control of some double stand reversing cold rolling mill was accomplished. The theory and implemental methods were discussed. The dynamics matrix control was applied in order to resolve the fluctuation of the tension control system. Simulation results indicated that the dynamics matrix control maintained the tension control precision.
Abstract: Automation systems for strip rolling mills are continuously being improved for the production of strip with high quality and low scrap loss. It is important to establish a process control system for the combined shape and gauge control system in hot strip rolling. The decoupling network for the multivariable system was designed based on the principle of feedforward compensation by considering the characteristics of the combined system. The decoupling single variable system has the characteristics of main channel of the plant. Considering the decoupling technological parameters of the 1 700 mm hot strip mill at Wuhan Iron and Steel Company, which vary widely with the rolling condition, gain scheduling decoupling control was developed for application in hot rolling. The developed mathematical model with library functions for gain scheduling is introduced and approved to be effective and has been applied in the production mill.
Abstract: Against the problems of time-delay, parameters-varyingness, large inertia, and non-linearity existing in AGC systems, a controller which combines adaptive centralized time-delay neural network recognition, optimal prediction and immunized fuzzy PID is proposed. The controller effectively improves the accuracy and dynamic performances of the system. Simulations in Matlab show that the controller is superior to traditional control strategies in all design criteria.
Abstract: Some algorithms about image processing and analysis in strip quality inspection were discussed. With plenty of strip images being captured from a hot-rolled steel strip line, evaluation and comparison to these algorithms were done with the rule of UMA (Ultimate Measurement Accuracy), which showed that the dynamic threshold image segmentation was the best and could be applied to the on-line width measurement of hot strip.
Abstract: The quenching and cooling of hot-rolling steel is a important step to improve the quality and mechanical properties of steel plates. It is the key to a quenching procedure to control the speed of cooling. Against the inherent shortcoming of the traditional quenching model and for the requirement of expanding steel varieties, specifications and improving the precision of quenching temperature, a temperature forecast model in quenching and control cooling was established by the method of neural networks. Combining this forecast model with the previous regression mathematical model, the real-times control of quenching and control cooling was accomplished. The result shows that the comprehensive model improved greatly the controlling accuracy of quenching and cooling.
Abstract: Based on the uncertainty theory, a measurement scale of uncertainty-blind number variance is defined. By dispersedly transforming the strong uncertainty in a wide interval into the weak uncertainty in a narrow interval, the numerical calculation principle and method of system uncertainty are also given. This is an all-purpose numerical value calculating method that is based on the blind number. Its correctness and practicability is perfectly proved by practical calculations.
Abstract: Based on the fuzzy language field, generalized cell automation and generalized inductive logical causal model, the mechanism of causal relation knowledge discovery were studied, and an algorithm of KDD with causal rules was proposed. With this algorithm, the causal relation knowledge discovery with uncertainty of random and fuzzy can be done effectively. An example illustrate the correctness and effectiveness of the algorithm.
Abstract: The distribution of internal stresses of the reinforcing ring assembling on a sewage disposal tower was analyzed by using the finite element method. The numerical results show that the reinforcing ring plays an important role to prevent the bulking of the combined shell from hydrostatic pressure and to provide a reliable structure strength when its transversal area is larger than 45 cm2.
Abstract: An adaptive background model based on Dynamic Information Window (DIW) was proposed. Using the adaptive background model, an effective human detection approach was presented. Experimental results demonstrated that the method can give a robust estimation of changing background models in real-time.
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
