Search

Fundamental theory of functions of basic tundish coving flux is analyzed at the first step. Several types of the flux used in deferent steel grade include ultra-low carbon steel, low carbon steel and micro-alloyed steel are involved . The result shows that the basic flux with CaO/SiO2 to be 3~5 can help to control the SiO2 be reduced by Al in steel within ±2%, and whole cleaness keeps stable with suitable component and proper process condition, marked with the T[O] content change ranged within 3ppm. But the basicity should be variable considering the productivity for different steel grade.

High volume fraction SiCp/Al composites were grinded in rotary ultrasonic vibration aided grinding in this experiment, exploring the effects of different grinding parameters (grinding depth, grinding wheel speed, feed rate) on grinding force and the material removal mechanism with ultrasonic grinding. The results showed that grinding force of ultrasonic grinding is lower than the ordinary grinding in the same grinding parameters. Studying on material removal mechanism of ultrasonic vibration grinding is bound to have important theoretical and practical significance for the improvement of grinding processes and the development of mechanical according to the advantages of grinding and ultrasonic machining. Keywords: High volume fraction SiCp/Al composites; ultrasonic grinding; grinding force

The elementary theory of functions of the basic tundish coving flux is analyzed at the beginning of this paper. Several types of the flux used in deferent steel grade include ultra-low carbon steel, low carbon steel and micro-alloyed steel. The result shows that the basic flux with CaO/SiO2 to be 3~5 can help to control the SiO2 be reduced by Al in steel within ±2%, and whole cleaness keeps stable with suitable component and proper process condition, marked with the T[O] content change ranged within 3ppm. But the basicity should be variable considering the productivity for different steel grade.

High volume fraction SiCp/Al composites were milled in ultrasonic longitudinal and torsional vibration high speed milling and high speed milling in this experiment, study on effects of different milling parameters (milling depth ap, feed engagement fz, the milling speed vz) on milling force. The results shows that in the same cutting parameters ,the three milling force of ultrasonic longitudinal and torsional vibration high speed milling are smaller than that of high speed milling, and milling forces of two milling method increase with the add of the milling depth and feed engagement ,but they aren't fold increase. Milling forces of two milling method decrease with the add of the the minlling speed,and the changes become gently when the the minlling speed run up to 170m/min, with the further increase of the milling speed,ultrasonic vibration high speed milling will translate to high speed milling, this is because the torsional vibration is submerged.

This paper introduces forming processing method by multiple spark electric sparks (EDM). This method can get more material removal rate, and reduce the power consumption.

This paper puts forward a model combined cloud computing and P2P, and then achieves chord resource search algorithm in the model. Because chord algorithm one hand, does not consider the problem of node heterogeneity, on the other hand, its routing table has large redundant information. So chord algorithm is improved from the two areas, and last MRC-chord is proposed. The algorithm first defines that the nodes of the same geographical form a ring, and in each ring, the node with strongest overall performance is selected to be super cloud node, all of the super cloud nodes form the master ring , then improves routing table. Experimental results show that: the improved algorithm can reduce average routing hops and average network delay effectively, so improves the efficiency of resource search.

The problem of stability for network-based singular control systems with time-delay and data packet is studied. In the presence of time-delay and random packet dropout, sufficient conditions for the existence of a feedback controller are derived, such that the closed-loop network-based singular control systems are exponentially mean-square stable in the mean-square sense. Then a linear matrix inequality (LMI) approach for designing such a controller is presented. Finally, a simulation example is used to demonstrate the effectiveness of the proposed method.

This paper is considering the surface quality control of hot-rolled coil. Through analyzing patterns, distributing-regularities and components of surface defect of low-carbon coil of WISCO, got the conclusion that mould powder entrapment was the key factor that lead the defect’s occurrence. Based on discussing the mechanism of powder entrapment in mould, developed a type of high viscosity powder, optimized flow field of mould through modifying the structure of SEN, and improved other relevant process conditions, the incidence rate of this type of defect was under controlled effectively and the degradation rate of the coil caused by the defect dropped from about 4 percent to less than 0.2 percent at the end.

The single-bucket excavator is one of the major equipment of the open-air mining with a long history of earth and stone mining and transhipment. The working conditions of its pushing and retracting pinions (also called gears) are very poor and they are wearing parts. Use WD400 excavator as an example, the paper specific analyze the failure of the pinions, point out the measures to extend their life from the point of view of structural design.

Bucket teeth of electric excavator used in metal mine bear severe impact and friction, so their life is short and this have an negative effect on productivity. The paper analyzes the case of failure and material of bucket teeth, and researches into the mechanism of abrasion of bucket teeth and distinguishing feature of the work hardening of ZGMn13, and draw the conclusion that it is correct to choose ZGMn13 as material of bucket teeth used in metal mine. Improve configuration of bucket teeth or enhance the abrasion resistance can prolong the service life.

High manganese steel is a wear-resisting steel. With the rapidly development of industry, it is very important to improve the wear resistance of high manganese steel. We do some experiments with cold asynchronous rolling technique on austenitic high manganese steel.The results show that hardness and impact abrasion resistance are enhanced greatly with the increase of deformation, and the toughness not decrease to very low.

For case of pulling inhibition and stagnation of slab casters appeared in one continuous casting department of WISCO, Factors include stress of dummy bar systems, integrated frictional force , compression force and pulling speed control mode are analyzed to get the causes. The case was ultimately changed with countermeasures such as equipment optimizing and technology improving. The stability and productivity of continuous casting was improved obviously as long as more benefit being provided.

Features and control methods in processes of unstable continuous casting of the 4th department of general steelmaking factory of WISCO were introduced, including ladle free-opening, tundish auto-casting, liquid level control and submerged nozzle’s quick replacing of mould, slag detection of ladle and so on. Countermeasures including updating facilities, improving accurate of controlling system, developing new technology were proved to be effective in practice, they can minimize the bad effect of the unsteady state to the producing stability and slab quality.

Hadfield steel is wear-resisting steel and widely used where the devices have high impact wearing performance requirements. Cold asynchronous rolling technique can improve the mechanical performances of high manganese steel to a certain degree. Through experimental research, this paper studied the effect of deformation degree and diameter ratio on its mechanical performances during asynchronous rolling.

On the basis of wholly analyzing the mechanism of the heat transfer in the 1880 regenerative furnace, the physical and mathematical 3-D model was set up to describe the heat transfer and combustion in the furnace, and the CFD software was used to simulate the whole combusting process in detail. From this, the law of the flow affected by four classical switching modes was studied in emphasis. The conclusions in the study were helpful to the reasonably design and optimization controlling of such furnaces.

By taking asynchronous cold rolling technique on austenitic high manganese steel (Mn13) specimens, the hardness of Mn13 specimens can increase. The reason for work hardening after asynchronous cold rolling is analyzed in depth by studying the microstructure and electron diffraction pattern. The research will make a contribution to theory and practice of Mn13.

Response surface methodology (RSM) was used to optimize sporulation medium components for improving spores concentration in I. lacteus fermentation broth. Five factors of sporulation medium components, glucose (X1), peptone (X2), yeast extract (X3) MgSO4·7H2O (X4) and VB1 (X5), were chosen to optimize through a five-level, five-factor central composite design (CCD) base on single factor experiments. The concentration of medium components which influenced the sporulation of I. lacteus was further optimized using RSM. The results show that The medium that consists of 4.15 g/L peptone, 2.04 g/L yeast extract, 5.10 g/L glucose, 0.17 g/L MgSO4·7H2O and 0.03 g/L VB1 enhance spores concentration significantly . The final spores concentration (2.19×105 /mL) by using the optimized medium was about five times higher than normal medium.

It is convenience to make plastic deformation by taking conventional cold rolling. By taking this technique on austenitic high manganese steel (Mn13) specimens, the hardness of Mn13 specimens increases. The mechanism of work hardening after conventional cold rolling is analyzed by studying the microstructure and electron diffraction pattern in depth. The research will make great significance to theory and practice.

By taking cold conventional rolling technique on austenitic high manganese steel specimens, their hardness increase. The microstructure is studied to analyze the reason why cold conventional rolling technique can create work hardening and improve wear-resisting performance of austenitic high manganese steel with the increase of deformation. The research will make great significance to theory and practice.

Miniaturization of all kinds of industrial product is a direction of development. Micro processing is the foundation of making the product miniaturization. This paper introduces the basic concept, technology level and main using ways of micro processing.

On the basis of wholly analyzing the mechanism of the heat transfer in the regenerative heating furnace，the physical and mathematical 3-d model was set up to describe the heat transfer and combustion in the furnace. Then the CFD software was used to simulate the combusting process of the whole furnace. At last, the flow and the temperature profile in the whole furnace were deeply studied and the flow character and the temperature distribution law in the furnace were revealed in detail. The conclusions here were helpful to the reasonable design and optimization controlling of such furnaces.

The emission of greenhouse gases leading to global climate warming has caused widespread concern on the part of governments worldwide. As one of the main sources of carbon emissions, modern logistics occupies a unique position for energy saving. But as economic entities, logistics enterprises have no real incentive to implement low-carbon logistics operations, which needs government to stimulate logistics enterprises to implement low-carbon strategy through regulations. Constructed an Evolutionary Game Model for logistics enterprises to implement low-carbon selection decision under the supervision of the government, analyzed the effcts of different regulative parameters on the implementation of low-carbon strategy in logistics business. The results show that government's regulation and strategies play a crucial role in carrying out the low-carbon strategy. Finally, according to different evolution conditions and conclusions, it proposes appropriate supervision strategies for government to promote logistics enterprises to put the low-carbon strategy into effect.

In this paper, the study of numerical simulation method used in jet molding CAE major technology is carried out, including simulation of filling flow process, keeping the stress process, cooling process, warping deformation and molecular orientation and so on; also makes a system induced study on injection molding CAE successfully applied in the injection mold design.

In order to study the effect of pre-deforming on the wearability of austenitic high manganese steel, domestic and foreign scholars did many pre-deforming tests. While the study of rolling pre-deformation is almost blank. By taking the cold asynchronous rolling technique, simulated roll test was carried out on austenitic high manganese steel. The microstructure and the performance after rolling showed that a great deal of high density twin crystals merged , the capability of work hardening and impact abrasion resistance enhanced greatly, wear-resisting performance improved with the increase of deformation.