Advanced Materials Research Vols. 156-157

Abstract: Relative motion between grinding wheel and workpiece makes the lubricant film pressure formed by grinding fluid in the grinding area increase, consequently, dynamic pressure lubrication forms. The grinding fluid flow field mathematical model in smooth grinding area is established based on lubrication theory. The dynamic pressure of grinding fluid field, flow velocity and carrying capacity of lubricating film are calculated by the numerical analysis method. An analysis of effect of grinding fluid hydrodynamic on the total lifting force is performed, and the results are obtained.

Abstract: In this paper, the parameter optimization problem for multi-pass turning operations is studied. A mathematical model based on the minimum production cost criterion is developed. The unwanted material is removed by one finishing pass and at least one roughing passes depending on the total depth of cut. Maximum and minimum allowable cutting speeds, feed rates and depths of cut, as well as tool life, surface roughness, cutting force and cutting power consumption are constraints of the model. Optimal values of machining parameters are found by three methods: integer programming, nonlinear programming, and genetic algorithms. An example is presented to illustrate the effectiveness of the optimization model and solution methods. The model generates lower unit production costs compared with the results from the literature and machining data handbook.

Abstract: As performance of processes in a manufacturing system determines the quality of product, the factors that have effects on the processes need to be taken into account to guarantee the product quality during manufacturing. As impacting factors’ effects are usually qualitatively described and hence result in difficulties of quantifying and evaluating, this paper proposes organizing a group of experts to evaluate the effects of the impacting factors and applying a fuzzy Impact-Matrix method to quantify the evaluation results. The proposed method provides engineers with a general perspective to identify important impacting factors and thus facilitates the control of processes.

Abstract: Blast-furnace gas produced from the process of iron making effectively can be used as fuel for engines to generate electricity for most middle and small steel enterprises. The effects of different component of blast-furnace gas, compressive ratio and ignition timing on combustion property of blast-furnace gas are simulated by GT-POWER software in this paper. The results show that flame speed and combustion rate will increase with the proportion of carbon monoxide and hydrogen increasing. There will be an optimized compression ratio value, under which the burning velocity is maximum. Within a certain scope, increasing ignition timing angle appropriately can improve property of combustion. A comparison of simulation and experiment result shows that the predictions give good results. All these results can help to optimize the parameters that affect the combustion, and provide certain reference for the further study blast-furnace gas engine.

Abstract: The theoretic formula for the optimal radius of elastic-plastic junction in auto-frettage thick-wall columnar pressure vessel was deduced. on the basis of the twin shear strength theory, the relationship between the allowable maximal operating pressure for the pressure vessel and yield was analyzed,Bauschinger effect to reverse yield with auto-engaged vessel was investigated, The procedure was illustrated with the help of numerical example and the results show the reliability of the designing method.

Abstract: The palladium based combustion catalysts on FeCrAl alloy substrate (Pd/FeCrAl) were prepared by electroless plating method. By means of scanning electron microscopy (SEM), X-ray diffraction and BET specific surface area, it was found that the prepared catalyst after calcination treatment at 800°C could obtain utmost PdO phases, which were well dispersed on substrate with small and uniform particles. The EDX analysis and the adherence tests further indicated that a synergistic interaction was formed between palladium components and substrate on catalyst calcined above 600°C, which might be caused by α-alumina whiskers packaging palladium particles on the surface of substrate. Moreover, the results of activity tests for toluene combustion showed that the 0.1%Pd/FeCrAl catalyst had good low temperature catalytic activity and temperature-resistance property. The total combustion temperature (T90) for toluene over catalyst calcined at 600, 800 and 1000°C was at 218, 207 and 217°C respectively. And the toluene conversion could keep up above 99% during the stability test of Pd/FeCrAl catalyst at 210°Cfor 50 h, indicating the good catalytic stability of Pd/FeCrAl catalyst.

Abstract: The paper proposes a space–time autoregressive integrated moving average (STARIMA) model to predict the traffic volume in urban areas. The methodological framework incorporates the historical traffic data and the spatial features of a road network. Moreover, the spatial characteristics in a way that reflects not only the distance but also the average travel speed on the links. In order to response the time-varying speed, six traffic modes are classified by level of service (LOS) which is updated in 5 minute interval. In the end, with the real traffic data in Beijing for experiments, the model achieves a very good accuracy on the 5 minute interval forecasting, it also provides a sufficient accuracy of 30 minute interval forecasting compared with ARIMA model.

Abstract: Honeycomb ceramics is the key component of the thermal flow-reversal reactor, which is for oxidation of coal mine ventilation air methane. In this paper, numerical simulation method was used to study the honeycomb ceramics' heat transfer process, and the effects of temperature difference and hole side length on heat transfer and the resistance losses were investigated. The calculating results show that the temperature difference between the gas and honeycomb ceramics is larger, then the heat transfer effect is better, and the resistance loss is bigger. In the situation other parameters are the same, then the hole side length is longer, the heat transfer efficiency is lower, and the resistance loss is smaller.

Abstract: In this study, pure and crystalline BaZrO3 powders are prepared by hydrothermal synthesis using of precursor of barium chloride and zirconium oxychloride. The influence of several synthesis parameters is studied. At high OH- concentration, it is possible to obtain the well-crystallized stoichiometric perovskite phase at relatively low temperature. In addition, We had prepared high purity powder took a mere 1h at 130oC. The phase and particle morphology of the product were characterized by the techniques such as XRD, SEM and chemical analyses. The results indicated that the morphology of grain corresponded to rhombic dodecahedron, and the product had a particle size region which is 2~5µm.

Abstract: To improve the quality of the steel plate, The No.2 Roll Mill of Wuyang Iron and Steel Company has adopted the hydraulic reversible 11 rolls leveler developed by Taiyuan University of Science and Technology and the Taiyuan Heavy Industry Co., Ltd. The machine uses a number of advanced technologies and new equipments. For example, this plate leveler uses the Supervisory Control and Data Acquisition system, including the main operator station, the monitoring station, engineer station, etc.It also adopts Oracle 10G database system and HP 380 Server clusters to realize the management function of technical data acquisition and analysis. It is able to complete the real-time data acquisition, data analysis, model calculation and self –learning function.