bluuebunny/crossref_metadata_2025 huggingface dataset:
Analysis on Influence of Dynamic Setting AGC Model Parameters on the Stability of Control System
Authors: Zhao Chun Jiang , Jiang Lian Yun , Zhang Jin Zhi , Huang Qing Xue , Yu Xiao Kai
Published: November 2010

Based on the theory of mathematical analysis, I find the rolling disturbance can be measured. Then the mathematical model of dynamic setting AGC is gotten by recursive methods. By the mathematical model I find out the influence of model parameters on the stability and convergence rate of the control system. When the system is stable, an influence of model parameters and parameter of the control system on steel strap thickness have been obtained, which will be helpful for us to choose suitable parameters in the end.
Optimization of Rolling Schedule in Tandem Cold Mill Based on QPSO Algorithm
Authors: Lin Sen , Nan Yu Rong
Published: November 2010

This paper adopts equal relatively load as objective function, and makes every parameter to meet certain restrictive conditions. SUMT algorithm was used to change constraints to non-binding conditions. QPSO algorithm was applied to optimize objective functions to obtain optimal solution. This algorithm was based on classical particle swarm optimization, which, with the conduct of quantum particle, had effective global search capability, good convergence and stability. As a result, reasonable distribution of tandem cold rolling power and full use of equipment capacity were realized, resulting in the improvement of production efficiency.
Analysis on Diffusion Parameters of Rolling Mill Bearing Alloy-Interface
Authors: Li Hai Bin , Huang Qing Xue , Wang Jian Mei , Ma Qin
Published: November 2010

In this paper, the diffusion quantity of different temperatures and unit time have been investigated basing on experimental results and theoretical analysis. The diffusing parameters of molten tin in the reaction process is investigated according to diffusing formula. The results within the range of 260～350°C indicates that the diffusing activation energy is increased with the time until the reaction ceases and it is decreased with the increasing of the temperature and substrate vacancy, but the average diffusing constant of tin increased with the temperature.
3-D Finite Element Simulation of the Vertical-Horizontal Rolling Process
Authors: Ruan Jin Hua , Zhang Li Wen , Yue Chong Xiang , Gu Sen Dong , He Wen Bin , Chen Shao Hui
Published: November 2010

In order to investigate the deformation behavior of a plate during a vertical-horizontal rolling process, a thermo-mechanical coupling analysis is carried out by three-dimensional (3-D) rigid-plastic FEM to simulate the process. The metal flow and the shape evolution of the plate are focused during this investigation. The thickness and the width of the plate agree well with the measured values.
Simulation of Automatic Position Control in an 8-High Cold Rolling Mill Hydraulic System
Authors: Wang Lin , Cheng Luo Ying
Published: November 2010

This paper presents the modelling and simulation of automatic position control (APC) in an 8-high cold rolling mill hydraulic system built by CERI (Capital Engineering and Research Incorporation). Key feature of the rolling mill APC system is introduced. From modelling, the servo valve and cylinder models are built, and from simulation the dynamic response of the system can be predicted for selecting system components and optimizing system performance. As system dynamic response is not only depending on the servo valve but also on all components in the system, root locus method is applied to analyze APC system dynamic response. Simulation results with different parameters are compared. Additionally, compared with a 6-high cold rolling mill APC system, the APC system dynamic responses of CERI 8-high rolling mill can reach better results than those obtained in the 6-high rolling mill system.
Research on Online Model of Vertical Rolling Force in Hot Strip Roughing Trains
Authors: Yuan Guo Ming , Wang Jian , Xiao Hong , Li Ming Lei
Published: November 2010

For low prediction precision of online model for vertical rolling force in roughing trains of hot strip mill, the process of hot strip roughing trains was simulated by the FEM simulation software DEFORM. The cause of low prediction precision of rolling force during vertical rolling was analyzed. Then the new method for calculating deformation degree when edge rolling was presented by analysis of the FEM simulated results. The formula of external stress status modulus, which is fit for the vertical rolling force calculation, was obtained by analytic regression. Furthermore, a new formula about rolling force calculation was gained. It was approved that the prediction precision was obviously enhanced compared with the practical data for vertical rolling force.
The Integrated Robust Control of Interstand Strip Tension for Tandem Cold Rolling Mill
Authors: Zhang Xiao Feng , Zhang Qing Dong , Yu Meng , Wang Kang Jian , Huang Pei Jie
Published: November 2010

We describe an integrated tension controller design for a tandem cold rolling mill in steel plants. To achieve stable rolling and ensure strip quality, it is very important to control the tension of the cold rolling mill. Previous researches examined only the operation of a single stand. But it is not sufficient to examine the operation and effect of whole stands because the operation is wholly interdependent. To solve the problem, this paper proposes an integrated control strategy for tension control of tandem cold mill, the full stand model for the tension system of a tandem cold mill is built, and the interaction of all the stands is analyzed. Then applying the method of μ-synthesis design a integrated robust tension controller. Simulation with the practical data proves the integrated robust tension controller can achieve more robust performance than that of typical industrial approach.
The Mathematical Models of the Best Adjusting of Shear Blade Clearance of Disk Shear in Cutting Plate
Authors: Huang Zhi Quan , Huang Qing Xue
Published: November 2010

In this paper the main factors of impacting the quality in cutting the plate between the Shear blade clearance adjustment and control were analyzed, Focused on further analyzing all relevant factors on adjusting the Shear blade clearance , combined with the accumulated process parameters in production of Thick Steel Plate Plant of He Bei Wen Feng Iron and Steel Co., Ltd. Proposed for the first time the mathematical models of the best adjusting of Shear blade clearance of disk shear in cutting plate.
Research on Quenching Equipment of Rail Head
Authors: Kang Hao , Wang Yong Hong , Wu Di , Zhao Xian Ming , Wang Yong Ming
Published: November 2010

As to current problem of straightness defects and uneven quenching thickness of rail head, heating device with several induction loops are used, and through a three step strategy to realize simultaneously heating to head and bottom of rail. In air jetting phase, spray nozzles are replaced by Al alloy plates(20mm thick) with holes, adjusting to cooling strengthen can be realized by changing cross-section of holes, cooling rate is 2~4°C/sec. After the air jetting phase, there is a waterfog jetting phase, which makes 200°C temperature gap between head and bottom of rail, to ensure quenched rail has good straightness after 48h natural aging.
Effect of Nozzle Layout Parameters on the Controlled Cooling of Flat Steel
Authors: Zhang Shao Jun , Zhu Dong Mei , Liu Guo Yong
Published: November 2010

The three dimensional unsteady cooling process of flat steel is simulated by the numerical simulation calculation method of Finite Element Coupling Field. Then, the influential rules, which about layout parameters of the controlled cooling nozzle such as the distance and number of nozzle rows on the cooling effect, are analyzed separately. The results show that the distance of nozzle has a little effect on cooling rate. Relatively the number of nozzle rows affects cooling rate of flat steel greatly. Different layout parameters of the controlled cooling nozzle will be used by considering different factors. The numerical simulation results provide references for the layout of steel nozzle and controlled cooling device.
MLE of Three-Parameter Weibull Distribution in Multi-Data Types
Authors: Wang Yu Jin , Fan Ying , Wang Shun Kun
Published: November 2010

An algorithm is presented for maximum likelihood estimation (MLE) of three-parameter Weibull distribution in this paper, which is not only suitable for uncensored data but also appropriate for various censored data. Firstly, a unified likelihood equation under censored data and uncensored data was built. Here, the second-order convergent Newton-Raphson iteration method was applied to solve the MLE of two-parameter Weibull distribution, which had only scale parameter and shape parameter with a given positional parameter. Then, the steady and rapid Brent search method was applied to solve the optimal solution of the likelihood function just with a single variable of positional parameter. Finally, several examples were given to demonstrate the stability and efficiency of this algorithm.
Analysis on Micro-Scale Behaviors of Pinch Rolls on Cut-to-Length Shear
Authors: Li Yu Gui , Wang Jian Mei , Liu Shao Peng
Published: November 2010

As one of the key devices of finishing line of medium & thick plate, pinch roll is mainly used for clamping, transferring and specialized lengths. Nowadays, there generally exist the off-tracking phenomena of pinch roll apparatus, the shearing and lengthening quality of steel plate are heavily influenced and the normal production of enterprise are disturbed. This paper introduces the micro-scale behaviors of pinch roll apparatus, deeply analyzes the reasons that result in off-tracking of pinch roll, and points out the corresponding solutions, which can provide theoretical guide to the design of new-type pinch roll.
Rigid-Flexible Virtual Prototyping Study of Planetary Gear Reducer for Shearer Cutting Unit
Authors: Zhang Ke Bin , Yang Zhao Jian , Zhu Wei Bo
Published: November 2010

In this research, three-dimensional simplified model for the planetary gear reducer of a certain large-scale shearer cutting unit is established by the use of UG NX5, and it is imported into ADAMS/View environment through the UG interface with ADAMS. While ANSYS is used to generate the flexible body of key parts such as sun gear, high-speed planet gear and low-speed planet gear, and then in ADAMS the flexible body is used to replace the corresponding parts of planetary reducer rigid body model, which aims to set up virtual rigid-flexible prototype model of planetary reducer. Finally, kinematics simulation was done. The simulation results show that the virtual prototype model of each component motion displays smooth without interference and the transmission ratio meets the design request. Meanwhile, the planetary gear mechanism design is proved to be very correct.
Analysis of Leveling Strategy for a Plate Mill
Authors: Cui Li , Hu Xian Lei , Liu Xiang Hua
Published: November 2010

In order to analysis the effect of leveling strategy on the quality of plate products, the curvature integration by elastic-plastic differences was adopted to simulate leveling results by different leveling strategy. It had studied plastic deformation ratio, residual stress, residual curvature and leveling force for different leveling strategies to find the effectual strategy and the adaptability conditions were given. Additionally, static pressure leveling with the time delay strategy was analyzed, which was proved to be an effectual strategy to resolve the leveling problem for high strength thicker plate by a certain 3500mm mill plate.
A Networked Control System of Rolling Shear Line Based on PROFIBUS-DP
Authors: Sun Zhi Yi , Sun Qian Lai , Yan Xue Wen , Li Hong
Published: November 2010

A networked control system is developed for a rolling shear line in this paper. In order to ensure the real time and reliability of communication, the PROFIBUS-DP is employed to structure a networked control system. Automatic cutting to length of steel plate is realized by that control system. The system has been running well since put to use, and the production efficiency is improved. Using the networked control system, not only it is easy to install and reconfigure, but also the costs of the setup and maintenance are reduced. The performance of the networked control system can satisfy the requirement of the rolling shear line.
Stress Testing and Strength Analysis of Vibrating Cooler
Authors: Yin Zhong Jun , Jin Ling , Chen Bing , Zhang Lian Wan , Tang Zhi Chao
Published: November 2010

For large vibrating cooler, which is belong to the rotary hearth furnace production line. It will produce a strong vibration at work, and it must satisfy a certain strength requirements. The service life of itself and whole production line are determined by the strength and overall stress level of the equipment. So, it is necessary to test and analyze the stress of vibrating cooler, and check its strength effectively.
Simulation of Average Model Switch Network of Power Converter
Authors: Song Yan Dong
Published: November 2010

The power converter connected to energy source and linear electric generator is crucial powertrain and converting component, and it is mainly used in hybrid electric vehicle. For switching the states of release energy and absorb energy quickly and smoothly, the accuracy of converter model is very important for designing of control system. The performances of converter can be evaluated by modeling and simulation before produce actual circuitry, so the converter model is created in average model switch network. Simulation results have a distinction between the two models with average model switch network and state equations separately. In comparison the average model switch network is more identical to practical system, so it is more valid for guiding design of control system of converter.
Simulation and Analysis of Mechanical Properties of Large Rotating Steel Structure Based on CAE Technology
Authors: Yin Zhong Jun , Tang Zhi Chao , Chen Bing , Han Tian
Published: November 2010

A reasonable finite element model of large rotating steel structure - rotary hearth furnace lower ring is established based on ANSYS. Simulation and analysis of the structure is processed on the lower ring. Stress distribution is achieved while bearing the weight of upper ring as the working condition. Spot stress testing is processed on the rotary hearth furnace lower ring. The overall stress distribution is obtained, and the finite element calculation results are verified, providing a reference for design and researches of similar large-scale steel frame structure in the metallurgical industry.
Work Roll Thermal Deformation Calculation Model of Cold Rolling Mill
Authors: Song Lei , Wang Jun Sheng , Shen Min Gang , Chen Xu Bo , Li Sheng Li
Published: November 2010

In this article, the factors which have influence on the work roll thermal deformation in cold strip rolling and the heat transferring mechanism are discussed. It is considered that there are three directions, radial, axis and circumference, for heat transferring for work roll thermal deformation. Therefore, it is a three dimensions unstable system for work roll temperature field of cold strip rolling. The plastic deformation work and friction heat are calculated by the divided element and digital integration method. The simplified calculation model is built for the heat transferring along work roll. There are four zones for work roll heat transferring: roll gap zone, air zone, emulsion zone, rolls contact zone. The heat transferring between the zones is decided by the temperature difference. The inter temperature field and thermal deformation of work roll can be calculated by two-dimension finite difference method. The work roll temperature and thermal crown of actual application cold rolling mill are analyzed by the model. By the comparison between calculated values and measured values, the work roll thermal calculation model can meet the accuracy requirement of on-line control.
Analysis of Contact Pressure between Rolls under Non-Symmetrical Roll Bending of UCM Cold Rolling Mill
Authors: Li Xu , Zhang Dian Hua , Wang Peng Fei , Zhang Wen Xue
Published: November 2010

. For UCM cold rolling mill, the intermediate roll shifting can enhance the ability of mill for better flatness control, but it will increase the non-uniform distribution of pressure between rolls, as result of a reduced roll life. In order to improve the contact state among rolls in rolling processes and to slow down the roll wear, the distribution of pressure between rolls under different forms of roll bending control has been calculated and analyzed by the influence function method in this paper. For the purpose of obtaining comprehensive information, not only the distributions of pressure between rolls with traditional work roll symmetrical bending and intermediate roll symmetrical bending have been analyzed, but also the distributions of pressure between rolls with non-symmetrical roll bending have been analyzed. All the analyses show that the work roll non-symmetrical bending as well as the intermediate roll non-symmetrical bending can play an important role in the slowing down of roll wear.
In Situ Test Study on Shear Strength Properties of Weathered Silty Mudstone
Authors: Li Zhang Ming , Chen Liang Liang , Wu Feng , Wan Ling
Published: November 2010

The shear strength characteristics of rock are very concerned in related underground construction. In this paper, in situ direct shear test for the weathered silty mudstone of the direct rock mass in a large section tunnel is carried out, the shear strength parameters are obtained, and some laws on the strength characteristics of this rock are got, such as that the displacement corresponds to the maximum shear stress under the given normal is decreased with increasing of normal loading number. This work provides a reference for the study of rock strength theory and its application.
Effect of Nd Content on the Microstructures and Mechanical Properties of As-Cast Mg15Al-xNd Alloys
Authors: Wang Hong Xia , Liang Wei , Xie Guo Yin , Xu Chun Xiang
Published: November 2010

Mg15Al-xNd (x=0, 0.5, 1.0, 1.5, 2.0and 4.0wt.%) alloys were prepared by metal mould casting method and the microstructures and mechanical properties were investigated. The results demonstrate that primary α-Mg grain is significantly refined with the addition of Nd element in Mg15Al alloy, and the best refinement is reached at 1.0wt.%Nd content. Further increasing Nd content leads to the coarsening of primary α-Mg grains. The added Nd element is also the reason of the refined eutectic β-Mg17Al12 and increased dispersion. The β-Mg17Al12 phase is thoroughly changed from fibrous coupled eutectic into divorced eutectic when Nd content reaches 1.5wt.%. Al11Nd3 phase is formed when the addition of Nd reaches to 1.0wt.% and Al2Nd phase emerges in the microstructure with increasing Nd content up to 4.0wt%. Addition of Nd element significantly improves the mechanical properties of Mg15Al alloy at room temperature. The best tensile strength and elongation is achieved by adding 1.0wt% Nd into Mg15Al alloy.
Research on Casting of GH3030 Superalloy with Electromagnetic Stirring
Authors: Zhan Guo Feng , Wang En Gang , He Ji Cheng
Published: November 2010

The effect of electromagnetic stirring on the inner quality and solidification microstructure of the GH 3030 superalloy ingots was investigated by casting experiments. As we know from the experiments, the solidification microstructure of GH3030 is the single-phase of austenite. With the electromagnetic stirring (EMS) the grains of the GH3030 ingots become finer significantly and the average grain size decrease as the currents of EMS increase. The results also show that the macrostructure of the ingots was improved significantly. The length of the shrinkage cavity with EMS become smaller and the porosity disappeared while the ingots without EMS have much porosity. And yet the macrosegregation always exists whether with EMS or not, but the chromium in the ingots with EMS is better distributed, and consequently the macrosegregation of chromium is inhibited.
Study on the Crystalline Morphology of Calcium Sulfate in H3PO4 and HNO3 Aqueous Medium
Authors: Jing Hong Jian , Zheng Xiao Xia , Fan Cai Mei , Feng Jun Qiang , Wang Yun Fang , Ding Guang Yue
Published: November 2010

This study aims to investigate the morphologies and the existing phases of calcium sulfate crystal by the reaction of H2SO4 with Ca(NO3)2·4H2O in acid medium using microscopic method and XRD powder diffraction. A series of experiments were designed for studying the crystal morphology and the hydrated form under coexisitence of phosphoric acid and nitric acid at 338K. The micrograph results show that in the H3PO4-HNO3-H2O system, the crystal shapes are changed from thick-long rod to thin-short rod, then needle-like even tiny needle gradually with the increase of acid content in solution. The solubility of calcium sulfate increases gradually with the increase of phosphoric acid or nitric acid concentration in solution. The XRD results show that with the increasing of acid concentration, the form of calcium sulfate is transferred from dihydrate to hemihydrate, that is, at higher acid concentration condition calcium sulfate hemihydrate is more stable in solution with the particles to be tiny and needle-like; while at lower acid concentration condition the crystals are mainly calcium sulfate dihydrate with larger rod particles which indicate a good filtration properties.
Electrochemical Migration Characteristics of Ag-Plated Cu Powders in Conductive Thick Film
Authors: Liu Yuan Long , Long Jin Ming , Zhu Xiao Yun , Liu Wen Jing
Published: November 2010

Silver electrochemical migration results in the degradation of surface insulation resistance, and has been attributed to the dendritic bridge between adjacent conductors. In this paper, the electrochemical migration behavior of both Ag-plated Cu powder and pure silver powder in conductive thick film (CTF) are investigated. By Electrochemical migration test (water drop+ DC bias method), and the SEM and XRD examinations, it was found that the silver electrochemical migration in CTF was minimized when the Ag-plated Cu powder substitute silver powder in CTF. This is ascribed to the galvanic coupling effect that plays an important role in the migration inhibition. As sacrifice anode copper restrains the cathodic silver from dissolving in solution so as to decreases the probability of dendritic growth.
A Study and Comparison of Calculating Grüneisen Parameter Using Different Methods
Authors: Zhang Ting , Wu Meng Qiang , He Ming , Xiong Jie , Chen Song
Published: November 2010

Some attempts for getting Grüneisen parameter are discussed. After comparing, the Grüneisen parameter got from Grüneisen EOS and Vinet EOS is consistent with the experimental data. However, we are not sure which method can describe the behavior of the Grüneisen parameter good under high pressures, because of the lack of directly measured data for Grüneisen parameter under high pressures. So, the technology for directly measuring Grüneisen parameter should be developed for clarifying this problem by experiments.
Characterization of Composite Coatings Produced by Plasma Electrolytic Oxidation Plus Cathodic Electrophoretic Deposition on Magnesium Alloy
Authors: Jiang Yong Feng , Yang Hua Shan , Bao Ye Feng , Zhang Ying Yue
Published: November 2010

The composite coatings were prepared on AZ91D magnesium alloy by plasma electrolytic oxidation (PEO) plus cathodic electrophoretic deposition (E-coat) to improve corrosion protection. SEM observation revealed that the organic layer was integrated with PEO film by physically interlocking; Potentiodynamic polarization(E-i) measurements in 3.5% NaCl solution, copper accelerated acetate salt spray(CASS) test and immersion test were employed to evaluate corrosion principle and corrosion rate of composite coatings. It is indicated that the corrosion resistance of composite coatings was improved obviously compared to the PEO film. There is no noticeable pitting corrosion on the composite coatings after 320h CASS test. The adhesion of composite coatings was evaluated by cross-cut and pull-off test. The results show that adhesion of composite coatings can reach to level 0 and 11.3 N/mm2 as a result of the blocking effect between organic layer and PEO film.
Tribological Performance of Ionic Liquids Bearing Hydroxyl Groups as Lubricants in the Aluminum-on-Steel Contacts
Authors: Li Xi Feng , Mu Zong Gang , Wang Xiao Xuan , Zhang Shu Xiang , Liang Yong Min , Zhou Feng
Published: November 2010

A series of room temperature ionic liquids bearing hydroxyl groups, namely 1-(3’-hydroxyl-n-propyl)-3-alkylimidazolium tetrafluoroborate or hexafluorophosphate, were prepared and characterized. Their typical physical properties were also determined. The tribological test results show that these ionic liquids possess better friction-reducing and anti-wear ability for aluminum-on-steel system than lubricant X-1P. The friction coefficients of them are little higher than that of the nonfunctionlized ionic liquid LP308, while they possess better anti-wear abilities than the latter, which may ascribe to the chemical activity of hydroxyl group. Both the anions and the side substituted alkyl chains attached to the imidazolium cations affect the tribological performance of the lubricants. The SEM, EDS and XPS analysis of the worn surfaces show that complicated tribo-chemical reactions were involved in the sliding process. The boundary films composed of fluorides, nitrogen oxide, BN, and FePO4 were generated on the rubbing aluminum surfaces, which contribute to effectively decreasing the friction and wear of the contacts.
Forming Limit of Sheet Metal Based on Different Property Imperfection
Authors: Yan Yu , Wang Hai Bo
Published: November 2010

From more than one uniaxial tension test curve, it can be found that mechanics property of sheet metal is inhomogeneous. Based on this truth, a new method for prediction of forming limit of sheet metal is proposed. Using this method, theoretical FLDs are obtained under proportional loading path based on Hill48 yield criterion. The effects of several material parameters on forming limit are obtained. Similarities and differences between this method and M-K instability theory are analyzed and some advices on the application of this method are given.
Effects of Repeated Plastic Working (RPW) Process on the Structure and Properties of Mg2Si/Mg-Zn-Er Composite
Authors: Li Shu Bo , Qin Ya Ling , Li Han , Du Wen Bo
Published: November 2010

The Mg matrix composite (Mg2Si/Mg-5Zn-2.5Er) was prepared using repeated plastic working (RPW) technique. and the effects of the number of RPW cycles on the microstructure and mechanical properties of these composites were investigated. The results indicated that the added silicon particles fully reacted with the magnesium matrix, and theMg2Si/Mg-5Zn-2.5Er composites were successfully achieved. When the number of RPW cycle increased, the size of the Mg2Si particles decreased, and the grain size of the matrix alloy reached the minimum when 200 RPW cycles was used. The best mechanical properties were also identified as 394 MPa ultimate strength, and 363 MPa yield strength, when 200 RPW cycles were used.
Electrochemical Properties of Li0.99Gd0.01FePO4/C Composite Cathode for Lithium-Ion Batteries
Authors: Sun Bin , Chen Yi Feng , Xiang Kai Xiong , Gong Wen Qiang , Chen Han
Published: November 2010

Li0.99Gd0.01FePO4/C composite was prepared by solid-state reaction, using particle modification with amorphous carbon from the decomposition of glucose and lattice doping with supervalent cation Gd3+. All samples were characterized by X-ray diffraction, scanning electron microscopy, multi-point Brunauer Emmett and Teller methods. The electrochemical tests show Li0.99Gd 0.01FePO4/C composite obtains the highest discharge specific capacity of 154 mAh.g-1 at C/10 rate and the best rate capability. Its specific capacity reaches 131 mAh.g-1 at 2 C rate. Its capacity loss is only 14.9 % when the rate varies from C/10 to 2 C.
Effects and Mechanism of Titanium on Cast Fluidity of ZG45
Authors: Wang Hai Tao , Xu Hui Zhong , Yu Hua Shun
Published: November 2010

The effects of titanium modification, which was added along with the pouring liquid in ladles, on the shrinkage porosity and cavity of cast steel ZG45 smelted in intermediate frequency induction furnace were studied. The metal liquid fluidity was measured by casting spiral samples. 0.2 wt.% titanium modification achieved the highest fluidity for steel liquid. Proper content of titanium could effectively increase the volume of concentrated shrinkage cavity, and restrain the forming of shrinkage porosity. By scanning electron microscope (SEM) and energy disperse spectroscope (EDS) analysis, it was found that TiC, acting as heterogeneous nuclei, could refine the structure grains, diminish the strong dendrite, and increase the fluidity and feeding capacity of steel liquid. However, overdoes titanium modification easily caused mass oxide TiO2, which kept solid phases with high meting point in metal liquid to increase its viscosity and decrease the fluidity. Meanwhile, these solid state titanium compounds enlarged the composition supercooling, so the metal liquid changed from sequential solidification to simultaneous solidification, resulting in inadequate metal liquid feeding, less oncentrated shrinkage cavity and serious shrinkage porosity.
Research on Surface Corrosion of the Adaptive Expandable Inner Bracing Screen
Authors: Ma Jian Min , Liu Yong Hong , Li Hang , Liu Zhi Fei
Published: November 2010

The surface corrosion mechanism of the adaptable and expandable inner bracing screen is introduced, experiment and analysis was made for the surface corrosion with the effect of temperature, chloride ion, calcium ion, pH value, this offer help to the application of adaptable and expandable sand control screen. The results show that surface corrosion rate is expedited with the temperature increase during 30 °C～80 °C, it reach the highest spot at 80 °C and then declined. The screen surface occur dot-corrosion easily in solution which contain chlorine ion, corrosion rate decline with the concentration increase of chlorine ion. Calcium ion can restrain the screen surface corrosion rate. Corrosion rate is decline with the pH value increase during the pH value of 3～6.
The Effect of Controlled Rolling and Cooling on the Microstructure Evolution of Boron Microalloyed Medium-Carbon Steel
Authors: Yuan Wu Hua , Fu Qiang , Zhou Heng
Published: November 2010

The processes of controlled rolling and cooling were simulated using hot compression tests on a Gleeble 1500 simulator with boron microalloyed medium-carbon steel. Effects of finish rolling temperature ranging from 760oC to 840oC and loop-laying temperature ranging from 660oC to 700oC on the microstructure evolution were studied. Experimental observations show that the average grain size of ferrite decreases while the volume fractions of ferrite and spheroidized pearlite increase when lowering rolling temperature. The maximum volume fraction of ferrite (62%) reached in our tests was obtained in the specimen whose rolling temperature and loop-laying temperature was 760oC and 700oC respectively. Excessive precipitation of the ferrite resulted in the carbon enrichment on some grain boundaries. Boron addition is effective to improve hot plastic deformation ability by removing nitrogen from AlN to form coarse BN particles on the grain boundaries.
Microstructure Evolution and Mechanical Properties of 780 MPa Hot Dip Galvanized Dual-Phase Steel
Authors: Li Guo Bin , Zhao Zheng Zhi , Tang Di
Published: November 2010

The microstructure evolution of 780 MPa hot dip galvanized dual-phase (DP) steel at heating stages of the annealing process was analyzed using a Gleeble−3500 thermal/mechanical simulator. A multifunction continuous annealing simulator was employed to investigate the effect of annealing process on microstructure and mechanical properties of hot dip galvanized DP steel. The experimental results show that ferrite recovery and recrystallization, pearlite dissolution and austenite nucleation and growth take place in the annealing process of hot dip galvanized DP steel. The hardenability can be significantly improved by trace addition of vanadium. When the soaking temperature reaches 780 °C, the tensile strength and total elongation of DP steel can reach 785MPa and 15%, respectively. The microstructure of DP steel mainly consists of a mixture of ferrite and martensite.
The Consistent Description of Crack Developing Process Based upon Cottrell' Pilling up of Dislocations Model
Authors: Yang Ai Min
Published: November 2010

The new concepts“crack nuclearation toughness”and “crack criterion number”given in this text were used for describing the different crack development steps and crack nuclearation critic condition and the fast developing critic condition of crack were suggested with them by means of Cottrellˊpiling up of dislocations model.The analysis pointed out that crack nuclearation toughness of brittle material is 1/2 of its fracture toughness and the criterion number of crack was a good parameter reflecting anti-crack toughness of material in crack developing process
Effect of Cobalt Additions on the Properties of Sterling Sliver Alloys
Authors: Xiang Xiong Zhi , Bai Xiao Jun , Chen Peng Xu , Yao Yong Gang
Published: November 2010

The objective of this research was to investigate the effect of Cobalt in as-cast sterling silver alloys used in jewellery industry on microstructure, mechanical properties, and tarnish resistance. The tarnish and corrosion resistance of sterling silver were improved with cobalt. This may be due to the grain refinement and the forming of cobalt oxide film on the surface of sliver alloy.
In Situ TEM Heating Study of the γ Lamellae Formation inside the α2 Matrix of a Ti-45Al-7.5Nb Alloy
Authors: Cha Li Mei , Clemens Helmut , Dehm Gerhard , Zhang Zao Li
Published: November 2010

In-situ heating transmission electron microscopy (TEM) was employed to investigate the initial stage of lamellae formation in a high Nb containing γ-TiAl based alloy. A Ti-45Al-7.5Nb alloy (at %), which was heat treated and quenched in a non-equilibrium state such that the matrix consists of ordered a2 grains, was annealed inside a TEM up to 750 °C. The in-situ TEM study reveals that g laths precipitate in the a2 matrix at ~ 750 °C possessing the classical Blackburn orientation relationship, i.e. (0001)a2 // (111)g and [11-20]a2 // <110]g. The microstructure of the in-situ TEM experiment is compared to results from ex-situ heating and subsequent TEM studies.
Reliability Analysis of LCF Life for a Turbine Disk
Authors: Gao Yang , Yang Chang Jun , Lin Kai , Gao Qing
Published: November 2010

Cyclic stress-strain curve and cyclic strain-life curve appear distinct scatters, and the scatter of fatigue life increases with reducing of the strain levels. A methodology for reliability simulation of low cycle fatigue (LCF) life for turbine disk structures is developed in this paper. First, probabilistic cyclic stress-strain model and linear heteroscedastic probabilistic cyclic strain-life model are founded based on the fatigue test data. Second, three dimensional model of a turbine disk is built, and the fatigue reliability analysis of this turbine disk is implemented in probabilistic design module (PDS) of ANSYS by the combination of response surface method (RSM) and Monte Carlo simulation (MCS). The predicted life with reliability 0.9987 is well consistent with the technology life obtained from disks LCF tests by scatter factors method.
Investigation on Aging Behavior of AZ91D Magnesium Alloy
Authors: Liu Guan Jun , Li Wen Fang , Peng Ji Hua
Published: November 2010

The aging hardening curve of AZ91D magnesium alloy was gained, and aging behavior of the alloy was investigated with Vickers hardness measurement, differential scanning calorimetry (DSC), transmission electron microscope (TEM) after solution treated at 415°C for 10h , and water quenched at room temperature , afterwards aged at 175°C for 0-38h with a 2h interval. The result show that there are three aging peaks at aging hardening curve of AZ91D magnesium alloy, and that four types of β-Mg17Al12 precipitates were responsible for the aging peaks.
Electroplating of Zn Coating on AZ31 Magnesium Alloy in ZnF2 Solution
Authors: Zhu Ping , Zhang Xin Jiong , Wu Jin Hua , Xu Yun Feng , Zhou Ming
Published: November 2010

Zn electrodeposited directly on the surface of AZ31 Mg alloy was researched in this paper. Zinc fluoride which was dissolved in ammonium citrate solution was used as metal ion source. The interface and morphology of Zn coating were observed by scanning electron microscopy (SEM).The results showed that Zn coating was smooth and dense. The experiment of making lattice on Zn coating showed good adhesion. The corrosion resistance of Zn coating was carried out in 5% NaCl solution, and its stabilization time was more than 5hrs. Cyclic voltammetry and polarization curve were used to investigate the transfer behavior and state of zinc ion in electrolyte. It indicated that Zn existed in the forms of three complex states in electroplating solution and ZnL proportion increased with increasing pH value. It was known that complex Zn electrodeposited directly on the cathode.
Effect of Different Filler Towards Welding of AA6061 Al Alloy by X-Ray CT Scan
Authors: Nur Azida Che Lah , Jalar Azman , Othman Norinsan Kamil , Rashdi Nasrizal Mohd , Ibel Md Zaukah
Published: November 2010

AA6061 Aluminum alloy welded joint using two different filler metals were studied by using X-ray CT-Scan. The filler metals ER 4043 and ER 5356 were used in this present work in order to investigate the effect of using different filler metals on the welded joint quality of AA 6061 aluminum alloy in welded zone microstructure. Gas metal arc welding (GMAW) technique and V grove butt joint with four layers and five passes welded joint were performed. From this investigation, it is found that AA6061 with ER 4043 showed less distribution of porosity compared to AA6061 with ER 5356 welded joint confirmed by X-ray Ct-Scan. The decreasing of porosities and presence of very fine grains in weld region area with ER 5356 compared to ER 4043 will be discussed in term of microstructure analysis.
Property Study on Novel Waterflood Conformance Control Gels
Authors: Ye Yin Zhu , Wu Xing Cai , Wang Zheng Bo , Wang Hong Tao
Published: November 2010

In order to improve the sweep efficiency of water flooding in matured oilfield, soft moveable gels (SMG) are developed. The new types of SMG are made of novel, expandable particulate materials. The gels are preformed, stable, size controlled, non-toxic and can reduce water permeability without affecting oil permeability significantly. In this paper, some relevant laboratory methods are carried out for the determination of their main characteristics, including the displacement mechanism, the physio-chemical properties, moblility in porous media and the adjustment of permeability. Furthermore, the properties in bottles and behavior in porous media have also been investigated. The results shows that: 1)the swelling times of SMG are approximately 10, 2)SMG can remarkably improve the efficiency of water flooding, 3)remaining oil startup in low permeability formation, multistage fluid diverting and deep profile control are the main oil displacement mechanisms, 4）the new promising gel system of SMG have extensive application prospects in deep water shutoff and conformance control.
Novel Biodegradable Polyurethane Foams Synthesized via Ring-Opening Oligomerization of Ethylene Carbonate Initiated / Catalyzed by Propylene Glycol / [bmim]Cl-(SnCl2) System
Authors: Zhou Jian Cheng , Cheng Ling , Wu Dong Fang
Published: November 2010

Poly ether-carbonate diols were synthesized by ring-opening oligomerization of ethylene carbonate (EC) initiated/catalyzed by propylene glycol/[bmim]Cl-(SnCl2) system. It was shown that the oligomerization was accompanied with decarboxylation and chain cleavage. The stronger the lewis acidity of ionic liquid, the better the catalytic performances. The biogradability of the polyurethane foams which was prepared by poly ether-carbonate diols (or common polyether polyos ZS-4110) and diphenylmethane diisocyanate (MDI) was determined by soil burial and found to be influenced by the content of carbonate unit, molecular weights and the hydroxyl value of polyols respectively. Poly ether-carbonate diols can reduce the amount of MDI in synthesis of polyurethane foams.
Fractional Exponent of the Modified Stokes-Einstein Relation in the Metallic Glass-Forming Melt Pd43Cu27Ni10P20
Authors: Ikeda Masahiro , Aniya Masaru
Published: November 2010

The diffusion coefficient in the metallic glass-forming systems such as Pd-Cu-Ni-P exhibits a marked deviation from the Stokes-Einstein (SE) relation in the proximity of the glass transition temperature. Such a deviation is characterized by the fractional exponent p of the modified SE expression. For the material Pd43Cu27Ni10P20, it has been reported that it takes the value p = 0.75. In this work, it is shown that the value of p is highly correlated with the ratio ED / ENB, where ED and ENB are the activation energies for diffusion coefficient D and cooperativity NB defined by the Bond Strength-Coordination Number Fluctuation (BSCNF) model. The present paper reports that for the metallic glass-forming melt Pd43Cu27Ni10P20, the fractional exponent p can be calculated accurately within the framework of the BSCNF model.
Dimethyl Ether Catalytic Combustion over Manganese Oxides with Different Structures
Authors: Yu Lin , Diao Gui Qiang , Ye Fei , Sun Ming , Liu Yue , Yu Qian
Published: November 2010

α-MnO2, β-MnO2 and Mn2O3 were synthesized from birnessite followed by acid treatment and subsequently calcined under different conditions. These catalysts were used for catalytic combustion of dimethyl ether (DME) and characterized by XRD, BET and H2-TPR techniques. The results showed that the catalytic activity of α-MnO2, β-MnO2 and Mn2O3 are higher than that of birnessite. Larger specific surface area as well as the better reducibility of Mn species in the manganese oxides might be the main contribution for the DME combustion activity.
A New Method to Measure Inertial Parameters of Rigid Body Based on Energy Decay Theory
Authors: Sun Ning , Wang Jin , Lei Fang Hua
Published: November 2010

Most measuring methods used now can only measure the rigid body’s six inertial parameters like the moment of inertia, the product of inertia and the centre of inertia toward to two-dimensional reference system. So a new method which can measure all the nine inertial parameters toward to three-dimensional reference system is proposed. The moment of inertia of object rotating the axis is obtained by energy decay method. Through using the translation and rotation transformation theory of product of inertia, the formula of moment of inertia including the information of product of inertia and centre of inertia is deduced. Then equations are built to solve all the parameters. Furthermore, a measuring instrument is designed based on the aerostatic bearing. Results show that this new method is available and by analyzing the experimental data, suggestions are made to improve this measuring method.
Experimental Investigation on Relative Crack Length For Fracture Toughness of Concrete
Authors: Wang Xue Zhi , Xu Zong Chao , Bi Zhong , Wang Hao
Published: November 2010

The wedge splitting test specimens with three series of different relative crack length were used to study the influences of relative crack length on the fracture toughness of common concrete. The suitable formulation for fracture toughness of concrete with different relative crack length was gotten on comparing between fracture toughness test results and computation results of the model developed from Hu formula.
Investigation of the Laser Melting Deposited TiAl Intermetallic Alloy on Titanium Alloy
Authors: Zhang Yuan Bin , Li Huai Xue , Zhang Kai
Published: November 2010

To improve the wear resistance of Titanium alloy, TiAl intermetallic claddings were fabricated on TC4 substrate using laser melting deposition technology. Optical microscope, scan electron microscope (SEM), energy dispersive spectrometer (EDS) and X-ray diffraction meter were applied to investigate the deposited TiAl layer and their interface with substrate. Using hardness tester and M-2000 wear testing machine, hardness, frictional coefficient and wear resistance of the TiAl layers and TC4 alloy were tested. It was indicated that the deposited TiAl layers were well integrated with TC4 substrate, γ-TiAl and Ti3Al dual phase microstructure was formed in the deposited layer. With higher hardness and lower friction coefficient, the deposited TiAl layer improved the wear resistance obviously comparing to TC4 titanium alloy substrate.
Application of Artificial Neural Network Based on GA-BP Algorithm to Predicting Mechanical Properties of TC4
Authors: Hou Zhe Zhe , Du Yan Liang
Published: November 2010

On the basis of numerous experimental results the effect of heat treatment on mechanical properties of TC4 alloy is studied. A computer model expressing the relationships between heat treatment and mechanical properties has been established with a back propagation feed forword artificial neural network method. The optimization methods based on artificial neural network and the genetic algorithm, using binary system, optimize the weight and threshold by the genetic algorithm. The calculation results show that the model has good learning precision and generalization and it can be used for predicting the mechanical properties of TC4 alloy.
An Analysis on Formation of ANF-6 Electroslag Fluxes Skin of Electroslag Remelting Ingot
Authors: Yao Jun Ping , Sun Zhong , Yang Wen Feng
Published: November 2010

The analysis on ingredient and petrographic examination of 5mm thickness ANF-6 electroslag fluxes (70% CaF2 + 30% Al2O3) skin formed during 0.45C steel 260 kg ingot remelting by electroslag remelting furnace with 160 kW, Φ100 mm × 350 mm mould indicates that the lamination phenomenon of fluxes is observed, and the Al2O3 content in fluxes skin near mould side and near electroslag ingot side is higher 69.24%-75.62%, and the CaF2 content is 21.46%-28.36%, where at skin center 3 mm location, the Al2O3 content in fluxes skin is only 15.84% and the CaF2 content is 81.06%. The solidification mechanism of “ring shaped miniature fluxes pool” formed at upper edge of remelted ingot is advanced in this paper, and the surface quality of ingot by using large over-cooling and low melting-point fluxes is higher than that by using low over-cooling and high melting-point fluxes.
Corrosion Behaviour of a Fe-Based Alloy in Zn and Zn-55Al Baths
Authors: Zhang Ju Cheng , Li Yan Xia , Zhang Yi , Liu Jun You , Liu Jie
Published: November 2010

Corrosion behavior in Zn and Zn-55Al baths were investigated on a Fe-based alloy, which was design to apply to hot-dip production lines as the anti-corrosion alloy. The results reveal that the Fe-based alloy shows excellent corrosion resistance both in pure zinc bath and Zn-55Al bath. And the reaction rate and intermetallic phase formation vary in different bath. In pure zinc bath, the intermetallic phases form on the Fe-base alloy is chiefly Fe-Zn phases contains Γ, δ and ζ phases. In Zn-55Al bath, the Fe-based alloy is comprised of Fe2Al5 and FeAl3 phases, and the outer layer is from bath itself. The more thickness the layer of Fe2Al5 phase, the more corrosion resistance of the alloy.