Knowledge discovery model of basic oxygen furance steelmaking based on Rough Set Theory

The characteristics of the knowledge discovery for basic oxygen furnace(BOF) steelmaking are analyzed by using the Rough Set Theory. The production data of BOF steelmaking are preprocessed by using the methods of data withdrawal, standardization, discretization and so on. The main influencing factors of steelmaking production are set as the knowledge discovery property. The endpoint control objectives of BOF steelmaking are used as the decision attribute of knowledge discovery. Then the knowledge discovery model of BOF steelmaking based on rough set theory is established, which makes the automation of the production knowledge discovery, access and rule extraction come true. The model is tested by using the production data of 210 t BOF, and takes the temperature variation of smelting endpoint as the decision attribute. The results show that the influencing factors, such as silicon content, iron ore weight, oxygen consumption and so on, are of very importance to the endpoint temperature of molten steel. Besides, the rules of molten steel temperature extracted by the model vary with current converter steelmaking process, which proves the validity of the model.     

BOF-caster matching model in steelmaking plant of all plate and strip using precision design principle

Using precise design principle, a multi-objective programming mathematical model of the BOF-Caster matched is established for single production line in the steelmaking plant of all plate and strip, according to the segmentation of steel grade and product specification of product mix. Objectives of the model have less investment, less difference between production capacity of the converter and continuous caster, higher operating rate of converter and higher level of weighted average casting speed. The model is solved by the improved delaminating sequence method. Then, the overall configuration method of BOF-continuous casting in the steelmaking plant is proposed through integrating single production lines. According to the production outline of a new large steel plant, the result of the model shows that the configuration scheme of the steelmaking workshop of the steel plant is a better design scheme.     

Production Planning Method for Steelmaking-continuous Casting Process Based on Time Backward and Process Simulation

Reasonable production planning effectively ensures smooth operation. According to the analysis of the characteristics of steelmaking-continuous casting production process, a production planning method for steelmaking - continuous casting process based on time backward inference method and process simulation is presented. Production plan meeting certain criteria is rapidly gained by time backward inference method, and is regarded as input of simulation model in steelmaking process. Considering time randomicity in production process and transporting equipment restriction, production plan meeting more restrictive conditions, such as no equipment conflict, continuous casting, and etc, is acquired through simulating. It assures that the plan is carried out in practice. The instance demonstrates the feasibility of the method.     

Optimization of a web based query system for a magnesium alloy database

Based on an existing magnesium alloy database, a query system is optimized by considering the design characteristics, and an integrated query system for this magnesium alloy database is developed to meet the demands of more users. The result shows that the new system improves the query efficiency of the magnesium alloy database, especially for queries concerning phase diagrams and the structure of magnesium alloys. This means that the new system provides users a more powerful and useful magnesium alloy database.     

Simulation method for multi-machine and multi-task crane scheduling in steelmaking plant

It is of great significance in steel complex to link production flow between work stations and control production rhythm by cranes. Crane scheduling is a multi-machine multi-task problem which limits temporal and spatial constraints and production plan. A simulation model based on evolution rules to solve temporal and spatial constraints is proposed. Its objective is to guarantee execution of production plan in steelmaking plant. And match between cranes and production task on working span is conducted to fulfill temporal constraints between multi-tasks and spatial constraints among multi-cranes. Simulation rules including task allocation, conflicts eliminating and task finishing are also proposed to dominate simulation process. This model avoids difficulties of theoretical calculation for crane scheduling problem. Offline test in a steelmaking plant shows that it is available to make a crane scheduling without conflicts between cranes and plans, which provides a guideline for production scheduling.     

Direct Alloying of High Speed Steel M2 with CaWO_4 MoO_3 V_2O_5

The principle and possibility of alloying of high speed steel W6Mo5Cr4V2 (M2) with CaWO 4 MoO 3 V 2O 5 during the steelmaking are discussed, experiments of the alloying technologcial process have been carried out, the properties of M2 product have been determined, the benefit have been analysed. The results show that the rate of recovery of W Mo V are respectively 97.08%, 96.51%, 93.79% during the steelmaking of M2 alloying with CaWO 4 MoO 3 V 2O 5 in induction furnace, the chemical composition and properties of product M2 can meet the demands that the standard of high speed steel M2 requires.     

Advance in Spray Forming Technology and Its Prospect

Spray Forming technology gets involved with new materials preparation techniques in multiple domains such as powder metallurgy, fluent metal atomization, rapid cooling and non-equilibrium solidification. High performance alloy and metal matrix composite with high density, low oxygen content and microstructure featuring rapid solidification can be fabricated by spray forming. Spray forming, which is of short process flow, low cost, high deposition efficiency, flexible manufacture system, becomes a kind of near shape forming and rapid solidification technology with great prospect. Therefore the developing process history of spray forming technology is introduced and the current research and development status of spray forming technology in the fields of aluminum alloy, steel material, magnesium alloy, copper alloy and high temperature alloy and metal matrix composite is described. Multi-layer spray forming and in-situ reaction atomization spray forming are also discussed. In addition, evaluation and prospect for the technology are presented.     

结构参数对水润滑橡胶合金轴承摩擦噪声的影响分析

为了研究水润滑橡胶合金轴承结构参数对其低速重载工况下摩擦噪声的影响,使用复模态分析方法建立了水润滑橡胶合金轴承系统仿真模型,采用专业仿真软件分析了不同摩擦系数及结构参数条件下摩擦噪声产生的概率,进而研究结构参数对摩擦噪声的影响,进行了平板型和圆弧型结构的水润滑橡胶合金轴承摩擦噪声的对比实验。研究结果表明,水润滑橡胶合金轴承的水槽半径大小、摩擦面形状以及摩擦副的摩擦系数对水润滑橡胶合金轴承的摩擦噪声有较大影响,而水槽的形状对轴承摩擦噪声的影响不大。对一定结构尺寸的水润滑橡胶合金轴承,水槽半径为4 mm、平面型摩擦面的结构可以大大减少轴承出现摩擦噪声的可能性,相关实验结果与计算结果是吻合的。     

Materials Hydrogen Storage V3TiNi0.56Al0.2 by Self-propagating High-temperature synthesis

With the help of the calculation of adiabatic temperature and thermodynamic analysis of the reactive system the autaurs discuss possibility about system of V 2O 5-TiO 2-Al by Self-propagating High-temperature synthesis(SHS).Hydrogen Storage V 3TiNi 0.56 Al 0.2 by SHS is studied by XRD,SEM and scanning electron microscopy.The experiment result indicates that it has same microstructure between synthesization by SHS and other ways.PCT curve indicated that alloy has certain hydrogen storage capability,saturated capacity of hydrogen storage is 0.092 L/g,which is a little lower than alloy by other ways.     

Prefabricated Building Construction-The Use of Aluminium Alloy Formwork

The Wah Wui System Formwork is a newly developed system formwork for industrialised housing in Hong Kong.The aluminium alloy formwork has lots of advantages,and the adoption of it can ensure the quality of concrete and therefore enhance the quality of housing. In this dissertation,the author introduces the design,materials of aluminium alloy formwork,and also the transportation,storage,installation,advantages and disadvantages of it.     

Loading behavior analysis of an aluminum alloy roof structure system under wind loads

The numerical analysis of a conventional aluminum alloy roof system taken from an actual international airport under wind uplift is conducted. A two-step simulation analysis approach is proposed, which effectively overcomes the computational difficulties brought by the contact between panels and supports. Through numerical analysis of roof components, the failure mode of the roof connection and the load bearing capacity of the roof are obtained. And the efficiency of material strength in each component is evaluated as well. It can provide reference for the design and application of aluminum alloy roof structure.     

A RESEARCH INTO THE Mn-Si-Cr AS-ROLLED DUAL-PHASE STEEL TREATED WITH TRACE B AND Ga

In this paper, the alloying of the as-rolled dual-phase steel treated with trace B and Ga is discussed. On the basis of Mn-Si-Cr alloy system, a new type as-rolled dual-phase steel containing trace B and Ga is developed, with a lower production cost equally high technological property, and similar CCT curve compared with that of the Cr-Mo system as-rolled dual-phase steel.     

Effect of the Carbonation on the Steelmaking Slag-Slaked Lime Mortar

The effect of the carbonation on the properties of the steelmaking slag-slaked lime (SmS-SL) mortar and its mechanism were mainly investigated. Furthermore, the environmental benefits of the SmS-SL mortar were discussed as well. Results indicated that carbonation could strengthen the SmS-SL mortar, reduce its drying shrinkage and improve its soundness. With the increase in the steel slag content, the strengthening effect of carbonation on the SmS-SL mortar is enhanced, but its dry shrinkage reduction effect is weakened. The SmS-SL mortar using steel slag exhibits significant environmental benefits. Its CO2 sequestration-efficiency and steel slag-recycle efficiency respectively reaches 6.4% and 27.8%.     

The Study on Smelting Ti-Si Ferroalloy by DC Electrothermal Process Using PISC Blast Furnace Titaniferous Slag

The new process for semiting Ti-Si ferroalloy using Panzhihua Iron & Steel Company (PISC) blast furnace titaniferous slag is introduced. The reduction and impoverishment law of TiO2 in slag and the effects of DC on smelting Ti-Si ferroalloy are studied when smelting Ti-Si ferroalloy by electrosilicothermal method,Ti-Si ferroalloy containing about 20% Ti can be produced by electrosilicothermal method. and Ti recovery rate is less than 60 %. And then, electrosilicoaluminothermal method is developed, by which Ti-Si ferroalloy containing Ti more than 30% and Si less than 35 % can be produced, and Ti recovery rate is higher than 80%. Ti-Si ferroalloy can replace TiFe martially in steelmaking,and residue slag can be used to make cement.     

Calculation model for the turnover number of steel ladle based on casting schedule

In order to realize optimization of production organization and put forward a reasonable calculation model for the turnover number of steel ladle, the turnover process and time of steel ladle are analyzed with steel ladle of Q steelmaking plant. Gantt charts of steel ladle turnover for single casting schedule and double casting schedule are drawn. Calculation model for turnover number of steel ladle is put forward by analyzing the relationship between casting schedule and the turnover time of steel ladle, and the accuracy of the model is verified by simulation method. Researches show that the turnover number of steel ladle can be reduced 1-2 by adjusting cast starting time, and have significance for the optimization of steel ladle production organization.     

Order planning for iron and steel enterprise considering production organization constraints

To realize efficient operation, the production organization constraints of ironmaking/steelmaking interface, desulphorization basic oxygen furnace and decarburization basic oxygen furnace, refining equipment and casting/rolling interface of typical steel production process A are analyzed. Order planning model of iron and steel enterprises considering production organization constraints is established. The scheduling compact and coordination and the optimization of commissioning date of different production lines are fully considered in the model. Then, the model is solved by tabu search. Finally, three different sizes of actual production contracts which are randomly selected from the steel plant A are simulated. The results prove the presented model and algorithm can harmonize and optimize the production effectively and also realize the process running efficiently.     

Water model study on flow optimization of five streams L-type tundish

In this paper, the water model method is used to optimize the flow behavior of asymmetrical five streams L-type tundish in a steelmaking plant. The results show that the optimization plan is set up with turbulence suppressor T+ vice guide wall D2+ main guide wall with three holes (D1a) which consists of top two holes with 25° inclination and one hole with 30° inclination below. With this plan, the time which the colorants reach to the outlets increases, the difference of response time in all outlets decreases, the peak concentration of the RTD reduces, the existence time of high concentration liquid steel extends, and the ratio of dead zone in each streams reduces.     

Optimal model on integrated production planning andscheduling of steelmaking and continuous casting process

Considering the uncertainty and complexity of production planning and scheduling in steel making and continuous casting, an optimal simulation model is built. Based on the analysis of the logistics in steelmaking process, the casting plan is regarded as the global goal, and the procedural information is taken into account, as well as the local evolution rule that abstracted from scheduling rule. To simulate transferring of materials in the process, the state of operation sites are updated as a result of the global goals, process information and local rule. The goal directed simulation is carried out based on the self organization evolution mechanism. Finally, an optimal integrated production plan is made by a continuous simulation evolution. A simulation case for eight hours production plan shows that the model is valid and efficient.     

Smelting AlMnSi alloy by Using High-bearing Manganese Slag

First smelting MnSi alloy by using high-bearing manganese slag of BF by electric smelting process in a 25 kVA arc furnace in lab has been introduced. In order to increase the content of manganese and silicon in MnSi alloy , a little amount of MgO is added into the slag and the lower alkalinity has been adapted. Then smelting AlMnSi alloy using MnSi alloy containing high silicon that obtained by experiments and waste Al with an induction furnace has been studied. The controlling of temperature is the key in smelting process. The high quality AlMnSi alloy has been obtained successfully,Which can be extensively used for the compound oxygen removal agent for making steel and the metal alloy additive.     

Calculation of the Thermodynamic Properties of Mg-Zn Alloy

Getting activity of component is an important aspect of researching the thermodynamic characters of alloy. Under each model of predicting the thermodynamics characters of alloy, Miedema model has been developing as comparatively a good and accurate model in recent years. In this work, the formation enthalpy of Mg - Zn alloy has been calculated, according to the Miedema model. Further, the activity curve of Zn in Mg - Zn alloy at 1 000 K is calculated. The calculating result is that, as the formation enthalpy of Mg - Zn alloy is small, and in the procedure of calculating activity, excess entropy attributes a lot to the result, after considering excess entropy, calculating results and experimental values match each other very well.