bluuebunny/crossref_metadata_2025 huggingface dataset:
Research on Corrosion Resistance of Titanizing and Nitriding on Carbon Steel in H2SO4 Solution
Authors: Bu Gen Tao , Gao Yuan , Wang Cheng Lei
Published: December 2011

Q195 steel was treated with titanizing followed plasma nitriding by glow plasma alloying technology using single pulse power supply. The corrosion resistances of titanizing sample and titanizing + ion nitrided sample were studied. The results show that the alloying layer is 200 μm in depth and organization is α-Fe solid solution containing Ti by plasma titanizing technology using single pulse power supply. An obvious reactive diffusion dividing line formed between alloying layer and the substrate. It shows that diffusion phenomenon happened in process of titanizing. The morphology of Ti alloy layer was columnar crystals. The content of Ti on the surface is up to 5 wt%. And the Ti content of alloying layer is in a decreasing from the surface to the inner on a gradient distribution. The phase structure of titanizing layer is composed of Fe2Ti, Fe-Ti and TiC phases. The phase structure of titanizing + ion nitrided sample was obviously TiN phase and a few Fe-Ti phase. The surface hardness of untreated carbon steel is 110 HV and that of the alloying layer of titanizing is 310HV. The surface hardness of titanizing + ion nitrided sample is 1800HV. The corrosion resistance of titanizing sample is increased 12.15 times compared with the untreated sample and 1.42 times compared with 18-8 stainless steel in H2SO4solution; The corrosion resistance of titanizing + ion nitrided sample is increased 7.444 times compared with the untreated sample and as well as 18-8 stainless steel in H2SO4solution.
Study on Blanking Force of Fine-Blanking with Negative Clearance and Common Blanking for AISI-1045 through Simulation and Experiment Methods
Authors: Fan W.F. , Li Feng
Published: December 2011

Fine-blanking with negative clearance is a kind of fine blanking processes. The punch size of fine-blanking with negative clearance is larger than the die size. The paper does lots of simulations for the changes of blanking force in fine-blanking with negative clearance and common blanking by DEFORM software, and the blanking force curves are gained by these experiments. The changing principle of blanking force and internal material is obtained through the simulation and experiments. The result shows that simulation blanking force of AISI-1045 is lager than the actual blanking force. According to the curves derived from experiments, we can see that the maximum blanking force of fine-blanking with negative clearance is higher than common blanking force. Compared with fine-blanking with negative clearance, the common blanking force reduces faster after the blanking force reaches maximum value. The experiment result shows that the force of fine-blanking with negative clearance under a smaller blanking clearance is a bit bigger than the force of common blanking force, and the blanking quality of fine-blanking with negative clearance is much better than that of common blanking. Cracks can be closed effectively by the special squeeze forming in fine blanking with negative clearance. Then, the crack can not expand continuously, and the bonding force is enhanced. The squeeze forming can restrain intergranular deformation and reduce the damage. However, the stretch forming easily leads to the inner crack and defect of materials. By means of the analysis on experimental curves, the paper further studies the changing law of fine-blanking with negative clearance blanking force.
Effect of Hydrogen Content on Impact Property of A357 Alloy
Authors: Li Yang , Xu Zheng Bing , Zeng Jian Min
Published: December 2011

The impact specimens with different hydrogen contents were solution treated at 540±3°C for 12h; water quenched at 60-100°C; and aged at 165±1°C for 6h. The impact test was carried out at Roell450 pendulum impact testing machine. The impact test results show that the impact energy has strong relation with the hydrogen content. The total absorption energy increases with the increasing of hydrogen content. The crack propagation energy Avp and present larger proportion than the initial crack energy Avi in the total absorption energy Av. The number of the pinholes increases and the pinholes turn from smaller irregular ones into sub-circular shape ones. The specimen with irregular sub-circular pinholes has larger KI, and has more crack propagation resistance.
Influence of Laser Parameters on Magnesium Alloy Surface Modification
Authors: Sun Kai , Yang Sen , Liu Feng Xia
Published: December 2011

It’s an important content to treat on the magnesium alloy surface for improving it’s abrasion performance and corrosion resistance in the field of surface engineering nowerdays. This research takes the AZ91D magnesium alloy and Aluminum as a substrate and powdered alloy respectively.It takes the laser surface modified technology as the method so that to enhance the corrosion resistance of the magnesium alloy surface.The optimization technological parameters are obtained by discussing the influence rule on laser power to corrosion resistance of AZ91D substrate and Mg-Al modified level.
Wear Resistance of Fe-Cr-C-TiFe Fe-Based Composite Coating Prepared by Precursor Carbonization-Composition Process and Plasma Cladding
Authors: Liu Jun Bo , Wang Li Mei
Published: December 2011

The sucrose was used as a carbonaceous precursor to fabricate composite alloy powder of Fe-Cr-C-TiFe by the precursor carbonization-composition process using the powder matirial of chromium, iron, tungsten, nickel and ferrotitanium. And the powder of Fe-Cr-C-TiFe was used to form a high-chromium iron-base composite coating on substrate of Q235 steel by plasma cladding process. The microstructure and hardness of the coating were investigated by scanning electron microscope (SEM), energy disperse spectroscopy (EDS), microhardness tester. Wear resistance of the coating was tested on wear tester at room temperature and high temperature 600°C compared with the base material Q235 steel and bearing steel. Results show that the coating consists of TiC, (Cr,Fe)7C3 and austenite and the hardness of the coating is 3.4 times as high as the base body Q235 steel. The wear resistance of the coating at room temperature is 11-15 times as high as the base body Q235 steel. The wear resistance of the coating at high temperature 600°C is 2.45 times as high as Q235 steel and is 1.5 times as high as bearing steel. The composite coating has excellent wear resistance because the reinforce phase TiC and (Cr,Fe) 7C3 in the coating have high hardness and good wear resistance. They can play key roles in process of friction and wear.
Variable Parameter Processes of Micro-Arc Oxidation for Aluminium Alloy
Authors: Gao Cheng , Xu Jin Yong , Shi Xuan Yi , Liu Ya Juan , Zhang Jing Chun , Zhang Guo Rang
Published: December 2011

In micro-arc oxidation process, ceramic coating had a rapid growth all along by the way of constant current oxidation, and ceramic coating had a low roughness by the way of constant voltage oxidation. But few research focus on the mixed control process of constant current oxidation and constant voltage oxidation. In this paper we propose a variable parameter process that can combine the advantages of constant current and constant voltage oxidation for the first time. The growth kinetics of different technics was analyzed according to the change law of current and voltage. Surface topographs of ceramic coating were observed using scanning electron microscopy (SEM). The friction tests were carried out using a self-made friction tester. The results show that ceramic coating has an upper growth rate and a low roughness by the process of constant current+constant voltage oxidation. The ceramic coating has a high growth rate by process of constant voltage+constant current oxidation. The results of friction test indicate that the wear rate and roughness of ceramic coating are positive correlation at early stage of friction. While the ceramic coatings treated by different technics have the close wear rate at stable friction stage, which embodies the inner layer of ceramic coating has a well antiwear behavior.
A Generalized Model for Residual Stress Caused by Thermal Mismatch in Multilayer Structures
Authors: Bai Yu Mei , Xu Ying Qiang , Zhang Tao
Published: December 2011

An analytical model based on multilayer structure with thermal expansion mismatch caused by temperature gradients was established to predict the residual stress in the system. The solution obtained from the model is independent of the number of layers. Three simplified models: bi-layer structure, coating system and film system with great compatibility are developed considering different engineering application. And the bilayer structure is verified by Stoney’s equation under the same conditions. Tri-layer coating system ZrO2/ Al2O3/1Cr18Ni9Ti is established in order to research the effect of temperature variations on the residual stress between different layers. The results suggested the stress has obvious mutation in coating interface with different temperature variation. And the residual stress with different temperature variation in different layers is larger than that with identical temperature variation. Key words: multilayer structures; residual stress; analytical model; thermal expansion mismatch; temperature variation
Creep Stress Analyses Affected by Load Properties on P91 Pipe with Local Wall Thinning under High Temperature
Authors: Xue Ji Lin , Zhou Chang Yu , Peng Jian
Published: December 2011

The local wall thinning defect is very normal on pipes in power plants, which may result in stress redistribution of the pipes during the service process at elevated temperature. For the purpose of understanding the stress redistribution and strain accumulation of pipes with local wall thinning affected by load properties under creep condition, three groups of models were calculated, using three-dimensional elastic-plastic finite element analyses (FEA) based on FEA codes ABAQUS. In this study, the pipes has an identical defect of local wall thinning, the load properties and values are changed. Three groups of load properties, considering here, were monotonic internal pressure, monotonic moment and both internal pressure and moment, respectively. The numerical simulation conducted on P91 full-scale steel pipes at 625°C, with local wall thinning located at the inner surface. Then, von Mises stress and creep strain of pipes after 100,000h could be obtained corresponding to different models. Based on the analysis, the figures of creep stress and strain varying with load properties were plotted. Then, the stress and strain of pipes with local wall thinning affected by load properties were discussed. The results indicate that creep stress and creep strain increase with load properties. The variation laws have been summarized. The research results can provide the possibility on safety assessment and structure integrity analysis of the pipe with local wall thinning at high temperature effectively.
In Situ Study of Fracture Process for B-Class Shipbuilding Steel
Authors: Wu Hui Bin , Liang Guo Li , Wen Y.H. , Yang C.C.
Published: December 2011

Crack initiation, propagation and microfracture processes of B-class shipbuilding steel have been investigated by using an in-situ tensile stage installed inside a scanning electron microscope chamber, meanwhile the secondary crack propagation at low temperature brittle fracture has also been studied. It is revealed that micro cracks always nucleated at the notch of specimens due to the stress concentration and then propagate along the interface of ferrite-pearlite. The plastic deformation of polygonal ferrite occurred in the loading process, the cracks propagated as “Z” morphology in the matrix. In the low temperature brittle fracture zone, the secondary crack propagated through the ferrite matrix in the manner of transgranular crack. When the secondary crack propagated to pearlite region, the intragranular crack and transgranular crack were observed in the pearlite region .
Optimal Riser Design by STL Arbitrarily Slitting Method and Genetic Algorithm
Authors: Shen Xu , Chen Li Liang , Zhou Jian Xin , Shao Xiong , Liao Dun Ming , Gong Xue Dan , Chen Tao
Published: December 2011

It is essential to consider the proper position and volume of riser during the design of feeding system. In this paper, we are presenting a new method of designing optimal riser in the steel casting processes. A technique of slitting arbitrarily 3D entity model by STL (Stereolithography) was used to obtain accurate values of the partial modulus of casting, and then a mathematical model of the process of the riser design was optimized by a genetic algorithm (GA); with the help of the CAE system, which has an ability to calculate automatically and verify the validity of the optimized results, we will pursue the goal of obtaining the desired riser with optimal size and distribution but without causing any defect in casting. Thus, by combining the numerical optimization with the traditional riser design, our method proposed here will be more practical and reliable. In the end, we give an example to demonstrate the feasibility of our optimized approach in the riser design. Keywords：Riser design, Genetic Algorithm, casting optimization, STL
Study on High Temperature Deformation Characteristics of BTi-62421S
Authors: Zhang Hui Fang , Zhang Zhi Min , Zhang Xing , Li Bao Cheng , Ma Hong Hai
Published: December 2011

In the paper, the high-temperature compression test of BTi-62421S alloy was carried out in the temperature range from 850°C to 1050°C, strain rate range from 0.01 s-1to 30 s-1, and the deformation of 70%. The results show that the flow stress of BTi-62421S alloy significantly increased with the decreasing of the temperature and the increasing of the strain rate. By calculating the activation energy of deformation and analyzing the stress-strain curve, it can be seen that the softening mechanism of hot deformation of BTi-62421S alloy is different near the （α+β）/β phase transforming temperature. The softening mechanism of hot deformation is mainly dynamic recrystallization in （α+β） area and it is mainly dynamic recovery above β phase transforming temperature. According to hyperbolic sine model, the alloy’s constitutive equation is established. Key word: BTi-62421S alloy; high temperature figuration; constitutive equation
Numerical Simulation and Analysis on Bending Forming of Hull Plate
Authors: Luo Lin Lin , Bi Da Sen , Bi Yan , Chu Liang , Ma Xu , Li Jian Ping , Di Hong Shuang
Published: December 2011

Bending process is one of the important methods to form thick hull plate, whose accuracy is directly related to the quality of hull plate forming.In this paper, bending process of thick hull plate is simulated by using finite element software ANSYS, and some simulation results on bending deformation of thick hull plate such as the deformation of meshes in deformation zone, the distributions of the Von Mises stress and effective strain are obtained.
Research on Air Quantitative Prediction Based on Mold Filling Simulation of High Pressure Die-Casting
Authors: Zhou Jian Xin , Liu Xin , Chen Li Liang , Chen Yang , Zou Fei , Liao Dun Ming , Liu Rui Xiang
Published: December 2011

Air-entrapped is a common defect for high pressure die-casting, so it is critical to discharge the air out of mold cavity as much as possible. This study takes the research on air quantitative prediction technology based mold-filling process. Firstly, the quantitative prediction technology is introduced and the mathematical model based on a simple die casting is established. Secondly, based on HZCAE technology the paper offers calculation module and post-processing module about air quantitative prediction. And then, water simulation is carried out to validate this air-entrapped prediction technology. Finally, combined with a die-casting case, we use the program to calculate its air quantitative prediction based on the simulation result of HZCAE/InteCAST. Keywords: Air quantitative prediction, HZCAE, High pressure die-casting, Numerical simulation, Mold-filling process
FEM Dynamic Analysis of Continuous Rolling Pass of Seamless Tubes
Authors: Feng Zhi Long , Ma Xu , Ma Jing Yun , Zhou Xiao Yu , Liu Hui Qiang , Ding Yan Hong , Li Jian Ping
Published: December 2011

The development of new products of seamless tubes require the development of corresponding grooves in order to manufacture tubes with high precision, high efficiency at low cost. In this work, a finite element model and dynamic simulation of continuous rolling pass for seamless tubes process has been implemented under the ANSYS/LS-DYNA environment to verify the validity of the pass design. The result show the deformation characteristic of cross-section, the variation regularity of rolling force, strain and stress conform to the reality. The work is effective for developing new grooves and products for seamless tube continuous rolling.
Formability of Tailor-Welded Blanks for Steel with Different Thickness and Materials
Authors: Li Yun Tao , Ye Juan , Song Ji Shun , Zhang Jian , Liu Guang Da
Published: December 2011

With the demands of environmental protection and energy conservation, increasing resources and improving environment, TWB (Tailor Weld Blank) as one of green re-manufacturing technologies will be a guiding orientation in industry. In this study, microstructure of welded joint、tensile test、fracture surface、cupping test of the TWB were carried out. Results show that the microstructure of weld is acicular ferrite and plate pearlite. The microstructure of HAZ beside SAPH440 is pearlite and grain ferrite, and the microstructure of HAZ beside DP600 is numbly pearlite and plate ferrite. The results of tensile test show that the shape of the materials after drawing is not easy to be rebounded, plastic deformation of the blanks is excellent, and the SEM of fracture morphology shows that the fracture is ductile and cleavage when the weld line parallels tensile axis. When the weld perpendicular to tensile axial, the deformation of the TWB is uneven, the plastic deformation is poor and the fracture is typical ductile rupture. The research results of the cupping test suggest that the bulging formability of the TWB is worse than that of base materials, and the bigger proportion of the thin blank in the TWB, the better bulging formability of the TWB. Introduction
Study on the Microstructures and Wear Resistance of ZG30Cr Steel Surface Layer
Authors: Wang Shu Li , Wang Ai Qin , Xie Jing Pei
Published: December 2011

In this paper ,the WC and high-Cr Cast Iron layer were obtained on the surface of ZG30Cr steel by casting-penetrating process, the organization and wear properties of penetrating layer were studied.The results show that the layer is dense, without pores, slag and other defects, the penetrating layer and substrate are metallurgical bonding. When 30 %WC and 70 % Cr-Fe with 100～120 mesh are added to permeability agent ,the penetrating layer has the best wear resistance, is 6.8 times the matrix materials. Keywords: The layer structure; Particle size; Wear resistance
Brass H62 Hot Extrusion of Micro Gear
Authors: Liu Xiang Ru , Zhou Xu Dong
Published: December 2011

Gears are very important and widely used driving components in mechanical instruments, and the demands of micro-gears are increasing more and more active as the MEMS technology develops in recent years. In this paper, a brass micro gear, which modulus m = 0.125 mm, pressure angle α = 20°, number of teeth z = 6, addendum circle diameter d = 1 mm, hot extruded from brass H62 billet with size Φ3×3 mm at 650°C was studied by experimental method. The microstructure of the micro gear was observed by scanning electron microscope and optical microscope, and the conclusions are as follows: the fiber flow lines within the micro-gear were formed by the extrusion, so that the anisotropic mechanical properties of the micro-gear was happened; The tissue distribution of micro-gear was that, the surface of the gear is almost entirely α-phase, while the internal part of the gear was the mixture of α-phase and β-phase, because the α-phase with lower hardness flowing outward to the surface of the gear during the extrusion process.
Forming Mechanism of Folding Defect within Closed Die Forming Car Steering Knuckle
Authors: Zhao De Ying , Zhang Lian Dong , Sun Li Na
Published: December 2011

Steering knuckle is the key part of vehicle steering system. The forming technology combined closed die pre-forging with open finish-forging has some advantages such as higher material utilization ratio and lower forming forces and so on. While simulating the closed die extrusion forming process of car steering knuckle, folding defect emerges on the contact area of Branch I and lower punch in the lateral extrusion process. The forming mechanism of the folding defect is studied by numerical simulations and experiments, which mainly consider the influence of lower punch shape and size, extrusion speed and friction conditions to folding length. The results show that the main factors that affect folding defects are the lower punch shape and size. Keywords: steering knuckle, folding defect, closed die forming, numerical simulation, experiment study
The Simulated Calculation and Optimizing Experimental Research of the Residual Stress of the Heavy Rail Straightening
Authors: Chen Lin , Wang Jian Guo , Li Ge
Published: December 2011

The finite element 3D model of heavy rail roller complex straightening is established by the finite element method in this paper.The straightening process is optimized by orthogonal experimentation and regression analysis. The formative mechanics and the regulation of the residual stress in the process of straightening are researched. The results of the simulation show that: whatever is on the basement of the residual stress or flatness, the new schedule is better than the real field one, residual stress is controlled within 250Mpa.
The New Technology of Softening Control for Copper Weld Joint Using Pretension Method
Authors: Zhou Guang Tao , Hou Wen De , Wang Zhe , Xue Zhong Ming
Published: December 2011

In conventional TIG welding, copper weld joint and its heat affected zone (HAZ) have the disadvantage of softening. In this paper, the new technology of softening control for copper weld joint using pretension method was studied. The results show that hardness of copper weld seam and its HAZ was increased by pretension. Moreover, the tensile strength and elongation of the welding joint were obviously improved. Keywords: pretension, weld joint, softening control, copper
A Study on Magnetic Separation Washability Mathematical Model of Pulverized Coal
Authors: Jiao Hong Guang , Li Sha , Pan Lan Ying
Published: December 2011

To further understand the magnetic separation washability of pulverized coal, washability curve and mathematical model were done based on internal relations of curves. The model included non-magnetic substance accumulated curve, ash characteristic curve and magnetic susceptibility curve mathematical model. The theoretical separation indicators and the non-magnetic product yield among the adjacent sub-selections susceptibility can be found and determined from these. We also can make a quantitative assessment of the magnetic separation washability and predict the actual results. Results showed that simulation results and experiments results can tally well according to choose reasonable parameters. Evaluation criteria of magnetic separation washability of pulverized coal has yet to make a further investigation. These indicate as a powerful tool of studying magnetic separation washability of pulverized coal can not only be qualitative reasonably but also investigate quantitatively. Key words: pulverized coal; magnetic separation; washability; mathematical model
Molecular-Dynamics Studies of the Diffusion of H2 in All-Silica ZSM-5
Authors: Du Xiao Ming , Huang Yao , Wu Er Dong
Published: December 2011

Molecular dynamics (MD) techniques were employed to simulate the diffusion properties of molecular hydrogen on all-silica ZSM-5 zeolite. The results indicated that in the temperature range of 77-293K and the pressure range of 14-3360 kPa, the diffusion coefficients are found to range from 1.2×10-9m2/s to 3.8×10-7m2/s, and increase with increasing temperature, and decrease with increasing pressure. The activated energy for hydrogen diffusion determined from the simulation is pressure-dependent. The diffusion of the molecular hydrogen in all-silica ZSM-5 zeolite channels is anisotropic duo to the increase of the temperature. The diffusion coefficients in straight channels are higher than that in zigzag channels. The difference results from the structural difference of the two channels and the different loadings of hydrogen. Keywords: Hydrogen; Zeolite; Diffusion; Molecular-dynamics simulation
Application of CAD/CAM Systems for Computer Simulation of Metal Forming Processes
Authors: Solomonov K.N.
Published: December 2011

It is shown that application of graphic techniques and CAD/CAM systems for solving problems of metal forming makes it possible to obtain satisfactory results. Using well known COMPAS graphical system, it is possible to plot diagrams of contact pressures for some special cases. PARSHTAMP software developed by authors enables to calculate boundary dividing lines of metal flow during deformation of flat preforms.
Study on Formability of Tailor Welded Blanks Based on Numerical Simulation
Authors: Liu Wen , Xie Shui Sheng , Li Ji Qiang , Ding Xu
Published: December 2011

The strength ratio, thickness ration of blanks and the microstructure of weld seam play important role in the formability of tailor welded blanks (TWB). With numeric simulation technology in different conditions such as different thickness and different strength combination of TWB’s materials, the forming limit depth (FLD) of tailor welded blanks is analyzed. The affect of the thickness ratio and strength ratio on forming limit depth is investigated, the laws influencing the formability of TWB square box are summarized, and approaches are presented to increase the FLD. The results of simulation and practice indicate that reducing the difference of the thickness ratio, choosing lower strength material for thicker blank, and adopting right heat treatment can improve the forming limit depth. Keywords: Tailor Welded Blanks; Forming Limit Depth; Thickness Ratio; Strength Ratio
Research on Tensile Stress Relaxation Characteristics of Pinus sylvestris
Authors: Li Xue Qi , Wang Xi Ming , Yu Jian Fang
Published: December 2011

This research aims to provide theoretical proof for the further study on the factors of stress relaxation under different conditions. In this study, use Pinus sylvestris and dynamic stress-strain test system, though change temperature and moisture to research the stress relaxation of wood. The results showed that the temperature and moisture content on the stress relaxation have a significant impact. With temperature enhancing or moisture content rising, stress dramatically relaxation and residual stress rapidly decreased. In other words, the initial stress decreased gradually and the relaxation rate was rise. It was also found that, under same conditions, compared with the tangential section of the Pinus sylvestris, the radial section has larger initial stress and smaller stress relaxation rate. Besides, the initial stress of late wood is larger than early wood but the stress relaxation rate is smaller. Key words: Pinus sylvestris, tensile stress relaxation
The Research on Relationship between Heat Generation and Crosslinking Density of Vulcanized Rubber
Authors: Fang Qing Hong , Zhou Shun Li , Wang Na , Zhang Xiu Bin , Wang Zhong
Published: December 2011

Crosslinking density of vulcanized rubber which was filled with carbon black and silica was experimentally researched, and its corresponding heat generation, dynamic lag loss (tanδ) and loss modulus ( E″) were also studied. Based on these tests, the model of the relationship among them was established. The results showed that the characteristic value of crosslinking density Vr almost showed downward trend as a straight line when the quantity of silica increased, but temperature rise, loss modulus E″ and tanδ increased obviously. Silane coupling agent Si-69 could improve the crosslink density and dynamic performance. In the drawing, linear correlation was good in linear fitting between temperature rise and loss modulus, as well as between temperature rise and tanδ. Keywords: vulcanized rubber; crosslingking density; heat generation; hysteresis
Solidification and Boride Characteristics of Boron-Containing Austenitic Stainless Steel
Authors: Wang Ming Jia , Bao Er , Wang Zi Xi , Zhang Shang Yi , Chen Chu , Li Yan Mei , Wei Hong Yu
Published: December 2011

Differential scanning calorimetry was used to study melt and solidification and microstructure of austenitic stainless steels containing boron. The liquidus and solidus temperatures decreased because of the boron content, and boron inhibited the formation of δ-Fe. A large content of eutectic boride structure was detected when the boron content was higher. The boride was M2B, and the crystal structure was orthorhombic. The crystal structure and elemental composition of M2B were investigated in detail by SEM-EDS and XRD analysis.
Analysis on Pyrolysis Products of Phyllostachys heterocycla in Heat Charring
Authors: Zhang Zhong Feng , Zhou Xian Yan , Ma Qing Zhi
Published: December 2011

Phyllostachys heterocyclabegins to be used for black bamboo with high added value. However, the pyrolysis products were severely wasted. Therefore, the chemical components fromPhyllostachys heterocyclawere identified by TD-GC/MS after concentration. The main constituents of 150°С volatiles were acetic acid (46.75%), carbon disulfide (4.90%), 2-furanmethanol (4.10%), benzofuran, 2,3-dihydro-(3.63%), formic acid (3.27%), 2-propanone, 1-hydroxy-(2.80%), 2-propenoic acid, 2-hydroxyethyl ester (2.64%), dimethyl ether (2.15%), .beta.-pinene (1.84%), camphor (1.71%), etc. The main constituents of 180°С volatiles were acetic acid (20.66%), benzofuran, 2,3-dihydro-(14.49%), furfural (8.86%), formic acid (8.37%), 2-furanmethanol (4.17%), 4h-pyran-4-one, 2,3-dihydro-3,5-dihydroxy-6-methyl-(3.74%), 2(5h)-furanone (2.83%), 2-propanone, 1-hydroxy-(2.74%), etc. The main components of pyrolysis products of Phyllostachys heterocycla in heat charring could also be used as bioenergy materials, but were not only abundant and healthy to human.
Study on the Coupled Structural-Acoustic Systems for Transport Aircraft
Authors: Chen Qi
Published: December 2011

The applications of sandwich structures in industry are numerous. The optimization of such structures with high strength and light weight have been the topic of interest for many researchers. There have also been a few studies on the vibration and sound transmission across these structures. This dissertation presents the structural and acoustic studies of sandwich structures for transport aircraft applications. The analysis of fully coupled structural-acoustic systems is presented in this paper. A method for the analysis of such coupled systems is developed using a particular solution approach. A simple two-dimensional rectangular cavity is used as an example to illustrate the solution approach in detail. Extensive numerical simulations have been done to investigate the effect of structural-acoustic coupling on the resonant frequencies and mode shapes of the system. The Galerkin and the Rayleigh-Ritz methods are used to obtain the coupled modal equations for the system which are solved using a state space formulation, which would provide the reference to the coupled structural-acoustic systems optimization.
Optimization of Structure Parameters for Hydraulic Energy Accumulated Torpedo Launching Device
Authors: Tian Bing
Published: December 2011

For the low launching noise and without increasing atmospheric pressure in chamber, the hydraulic energy accumulated torpedo launching device has been highly regarded by all navies around the world. Mathematical mode of the launch course of the device has been built. Combined with the tactics and technique index, the structure parameters of the device have been optimized with genetic algorithm. As several parameters which were different in degree and range, normalization was applied to convert multi-objective optimization into single-object optimization, and penalty function method was used to deal with constraints. The optimization result shows that the optimized structure parameters not only meet the requirement of launching, but the dimension of the device is more compact to fit the narrow configuration of submarine and may provide references to the design of hydraulic energy accumulated torpedo launching device.
Consolidation of High-Level Radioactive Wastes into Strontium Titanate by CS Method
Authors: Zhang Rui Zhu , Yang Jie , Yan Da Kao , Guo Zhi Meng , Su Wan Shan
Published: December 2011

Strontium Titanate synroc samples were synthesized by combustion cynthesis (CS). Sr directly took part in the synthesis process. As a result, loading content issue is basically resolved. The products were characterized by density, microhardness X-ray diffraction, and scanning electron microscopy (SEM/EDS). The leaching rate was measured by the method of PCT. The results indicate that the Sr2+-SrTiO3 compound with high density, low leach rate and high property stability and the synthesis process is feasible in technology and economy. It can be concluded that the Strontium Titanate synroc is a perfect material to immobilize HLW Keywords: Strontium Titanate, high-level radioactive waste (HLW), immobilization, self –propagating high –temperatures synthesis (SHS).
Internet Based Shared Control of Vehicle Steering when Driver Is under Situation of Tendency to Accidents
Authors: Zhong Ming En , Wu Ping Dong , Peng Jun Qiang
Published: December 2011

Probability of traffic accidents grows when the driver is under situation of tendency to accidents. This paper introduces a new vehicle model under internet based shared control technology, modeling towards the internet based shared control of steering system. Influence of the network transmission delay on the steering performance is simulated, and a closed loop control circuit model is created. A systematic controller algorithm and input gain range from the viewpoint of the sufficient condition for delay dependent robust stability and steady state error are put forward. Finally, a dynamic self-switching delay-dependent robust controller is designed and showed at the end of the paper. Simulation and experimental results show the validity of the proposed method.
FEM Modelling and Press Signature Evolution of a Typical Car Stamping
Authors: Sekeres Thiago , Fernandes Cleber , Santos José Carlos , Nunes Eduardo , Plaut Ronald Lesley
Published: December 2011

A typical car stamping is analyzed in terms of FEM and its press signature is evaluated in detail. Microstructural, crystallographic texture and surface roughness evolution are studied in conjuntion with press performance. Careful press signature calibration is discussed in order to point out relevant aspects. Deep drawing steels are analyzed in terms of their evolution in microstructure and texture and path-related to the FLD (Forming Limit Diagram). 3D-Surface roughness is tentatively evaluated and related to the steel stampability.
A Study of Numerical Modelling of Liquid Filler Flow within Braze Gap on Vacuum Brazing
Authors: Li Pei Yao , Yu Zhi Shui
Published: December 2011

A three-dimensional computer code which is employed for modelling of fluid flow and heat transfer during braze gap filling on vacuum brazing has been developed by using SIMPLE algorithm and VOF method. By the aid of this program, the flow behavior of liquid filler metal, the location and wave of the free surface, as well as the temperature distribution can be simulated. In order to verify the computational results, experiments of vacuum brazing thin plate weldment with 0.03mm and 0.2mm braze gap have been made respectively. The result of comparisons between calculated data and experimental data show that the brazing gap is one of the most important technological parameters that influences the flow pattern of liquid filler metal during braze gap filling and the brazing seam formation process significantly, and the 3-D modelling of braze gap filling are rather accurate and reliable, thereby providing a useful and effective analytic tool for brazing technological design. Keywords: vacuum brazing; brazing gap filling; numerical modelling;
Study on the Ball Joint Sealing of Aluminium Control Arms
Authors: Tian Hao Bin , Liu Xiao Hang , Yu Zhong Tu
Published: December 2011

The control arms, as an important part of automobile chassises, are using Aluminum alloy in more and more cases instead of steel. The ball joint sealing of control arms is a key process to chassises assembly and the sealing quality directly determine the lifespan of steering systems of automobiles. In this paper, based on the aluminum control arms, revolving-reveting processes for ball joint sealing of control arms are studied through finite element methods and experiments, and the effects of housing shape on the quality of ball joint sealing are also studied. The results show that the sealing quality for ball joint is related to the housing shape, and a better sealing quality can be achieved when the housing has a sloped edge, and verified by the experiments, which will provide elementary technical support to the ball joint sealing of automobile control arms. Keywords: Ball joint sealing; Revolving-reveting technology; Aluminium control arm.
Virtual Optimization of Regulating and Controlling on Welding Residual Stress of Francis Turbine Runner
Authors: Ji Shu De , Liu Xue Song , Yang Jian Guo , Liu Zhen Lei
Published: December 2011

In order to solve the problem of crack appeared in Francis turbine runner, the welding residual stress of Francis turbine runner is regulated and controlled by means of numerical simulation from the view of subsection welding, local heating and local peening. The results show that the length of welding section of blade outlet and the welding direction in the subsection welding process influence the residual stress of the turbine blade. For the local heating technology, the decreasing effect on residual stress increases with the increase of heating time, heating temperature and heating area. The welding residual stress of dangerous region decreases and then increases with the increase of heating distance. Moreover, the peening effect is very clear when the temperature of material in the peening region reaches its own plastic temperature.
Investigation on the Welding Temperature Field Measurement in Gas Tungsten Arc Welding
Authors: Zhou Guang Tao , Zhao Zi Yu , Liang Guo Li , Chen Wei Hua
Published: December 2011

Based on the gas tungsten arc welding process this paper investigated the welding temperature field measurement and simulation of 945 steel plate and AZ31B magnesium alloy, using a non-contact and fast response measured temperature method-Infrared Radiation (IR)-which utilized the baffle to remove the arc and hot tungsten electrode interference, the top-face temperature of AZ31B magnesium alloy plate and 945 steel plate. The results indicated that the lengthwise isothermal map of 945 steel plate is much longer than that of AZ31B magnesium alloy plate, which leads to the most temperature field information loss, this is because the thermal conductivity of steel is small and decreases with temperature increase, the thermal conductivity of AZ31B magnesium alloy is much bigger that that of the 945 steel, about 1.5 times of 945 steel, and increased with temperature increase. The results also showed using IR to measure the welding temperature of magnesium alloy is more difficult than 945 steel. Keywords: magnesium alloy, high strength steel, welding temperature field, IR
The Defects Analysis and Numerical Simulation of Automobile Brake Hydro Cylinder in Permanent Casting
Authors: Rao Lei , Zhu Lian Bing , Li Xiao Long , Hu Qi Yao
Published: December 2011

Brake hydro cylinder is the key part of automobile hydraulic braking system, which usually works under high pressure condition. So, high safety factor of it is required to avoid accident. There are many kinds of casting defects such as shrinkage cavity, gas entrapment and slag enclosure are formed in the mold filling and solidification processes, which contribute to final casting performance. Based on the mathematical models of molding filling and solidification processes, the numerical simulation has been done. In the meanwhile, the defects forming reasons have been analyzed. According to the simulation results, two types of improved schemes have been analyzed and practiced respectively, and its work piece defects were reduced largely. It is an effective way to improve the casting quality by advanced computer technology.
Elements Diffusion Asymmetry in Transient Liquid Phase Diffusion Bonding of Dissimilar Metals
Authors: Gao Zeng , Chen Si Jie , Xu Qin
Published: December 2011

12Cr2MoV steel pipe and T91 steel pipe were joined by transient liquid phase diffusion bonding process (TLP) in argon atmosphere using FeNiCrSiB amorphous filler. TP304H steel pipe and 12Cr2MoV steel pipe were joined by the same method using Fe78Si9B13 and BNi2 amorphous filler. The qualified welding joint can be achieved by suitable adjustment of process parameters. The diffusion asymmetry in TLP of different metals has been analyzed. The research shows that there exists a diffusion asymmetry in TLP of different metals. The main reason is the difference of isothermal solidification rate in different materials, which results in a deviation of the bonding interface from the original centerline to T91 and TP304H side.
Investigation and Numerical Modeling of the Process of Cold Rolling HSLA Steels
Authors: Mazur Igor , Dolmatov Aleksandr P. , Borisov Sergey S.
Published: December 2011

Considering the problems and details of modeling process of cold rolling, it was constructed a theoretical model of deformation area based on a set of equations, which were practical testing. The model is based on cold-rolled numerical solution of differential equations of forces equilibrium in the deformation area by Karman. In the model there are included modules for calculating strip temperature and strip gage at the exit from the stand, considering elastic recovery of the strip. For adaptation of the equations to the specific conditions of cold rolling of HSLA steels in the continuous five stand mill 2030 and assess the deviation of calculated data from the actual, a procedure of correction for hardening curve of rolled steel has been developed. The model allows defining the energy-power parameters of rolling: average unit rolling force, the full force of rolling, rolling moment, rolling force, an average temperature of strip at the inlet and outlet of each of the mill stands, steel hardening curve when rolling. The model is implemented as software using object-oriented approach in the language of C++ Builder.
Characteristics of Embrittlement in Weather Resistant Steel in Austenite and γ-Ferrite Temperature Range
Authors: Gao Xing Jian , Chen Deng Fu , Song Li Wei , Hu Hui , Yang Xing Lei , Wang Guan , Zhou Zhen Yu
Published: December 2011

The embrittlement of particular weather resistant steel has been investigated by thermal tensile tests using a Gleeble-1500D system at temperatures range from 600 to 1300°C and at a strain rate of 10-3/s. The specimen was reheated and cooled to the test temperature before the tensile deformation in order to get the mechanical properties subject to the continuous casting process. To make clear the plastic flow behavior in Austenite and γ-Ferrite temperature range of the weather resistant steel, the tensile tests were performed and the results indicate that the stress-strain curves as a function of temperature and with the temperature increased the stress became less, while the hot ductility changed significantly due to the work hardening and recrystallization. All of the strength indices (including yield strength, tensile strength and fracture strength) of the steel increased gradually with decreasing temperature, except for small fluctuations during the γ→α transformation occurred. Special emphases were placed on the hot ductility to clarify the sensitivity of surface cracking during unbending operation and the embrittlement zone occurred in the temperature range between 750 and 1050°C, in which the minimum %R of A was around 22% at 850°C. In the embrittlement zone, the specimens were fractured with little plastic deformation by either grain boundary sliding or by localization of strain in the film proeutectoid ferrite produced by the γ→α transformation. Keywords: Weather Resistant Steel, Embrittlement Zone, Stress-Strain Analysis, Hot Ductility, Fracture Surface.
Corrosion Resistance of Ceramics and High-Temperature Phase Change of Powders on Cubic Silicon Nitride
Authors: Yao Huai , Zhu Guang Lin , Du Meng
Published: December 2011

An installation, consisting of an explosive-driven planar flyer and a cylindrical chamber, was designed to synthesize γ-Si3N4 with cubic spinel structure using the mixtures of impure α-Si3N4 and copper powders as starting materials. Sintering of γ-Si3N4 with Y2O3-Al2O3-La2O3 as additives were studied under pressures of 5.7 GPa and temperatures of 1370K. The corrosion resistance of γ-Si3N4 sintered compact to hydrofluoric acid was investigated at temperature between 490K and 500K, and its thermal stability of γ-Si3N4 powder prepared by shock wave synthesis was studied at temperature between 1670K and 1690K in a nitrogen atmosphere. The results show that γ-Si3N4 sintered compact could not react with hydrofluoric acid at 490K. At 500K, γ-Si3N4 sintered compact could reaction with hydrofluoric acid slowly, and 0.2g γ-Si3N4 sintered compact quality reduced 0.013g after 6h. The γ-Si3N4 sintered compact could not react with hydrochloric acid, nitric acid, sulfuric acid and universal solvent at 500K. The γ-Si3N4 powder was quite stable and without phase transformation at 1670K, and after soaking at 1680K for 10 min and 30 min, the ratio of transformation from γ-Si3N4 to β-Si3N4 is about 0% and 80%, respectively. The γ-Si3N4 powder could be completely transformed into β-Si3N4 after soaking at 1690K for 30 min. Keywords: cubic silicon nitride; shock wave synthesis; phase transformation; corrosion
Effect of Ultrasonic Vibration Grinding for Mechanical Properties of Al2O3/ZrO2 Ceramics
Authors: Zhu Yao Min
Published: December 2011

The effect of ultrasonic vibration grinding for mechanical properties of Al2O3/ZrO2 ceramics composite was studied in this work. The phase compositions and the microstructures of Al2O3/ZrO2 ceramics were investigated by XRD, SEM and TEM. Results indicated that the hardness and fracture toughness of Al2O3/ZrO2 ceramics could reach 1496Mpa and 9.44 MPa.m1/2 respectively, which increase 60% and 12% compared to that without ultrasonic vibration grinding.
Effects of High Magnetic Field Heat Treatment on the Microstructure of Fe-0.76%C Alloy
Authors: Gong Ming Long , Zhao Xiang , He Chang Shu , Song J.Y. , Zuo Liang
Published: December 2011

The present studies are to investigate the microstructure features during transformation from austenite to ferrite without and with magnetic field on Fe-0.76%C alloy. It is found that the area fraction and numbers of proeutectoid ferrite grain as well as the lamellar spacing of pearlite in Fe-0.76%C alloy increased considerably with the increase of magnetic field intensity. The reason is that, the magnetic field increases the driving force of proeutectoid ferrite nuclei and shifts the eutectoid point to the side of high carbon content and high temperature, which increases the starting-temperature of the transformation from austenite to ferrite. The proeutectoid ferrite grains are elongated along the magnetic field direction, which can be explained as follows: the proeutectoid ferrite becomes the magnetic dipolar under high magnetic field, and then the polarized austenite atoms are much easier to diffuse into ferrite grains along the magnetic field direction. Key words: high magnetic field; Fe-0.76%C alloy; microstructure