bluuebunny/crossref_metadata_2025 huggingface dataset:
Prediction of High Cycle Fatigue Property of Ti-6Al-4V Alloy Using Artificial Neural Network
Authors: Zhao Ye Man , Kou Hong Chao , Wu Wei , Deng Ying , Tang Bin , Li Jin Shan
Published: March 2016

In this paper, the relationship between microstructure, parameters of cyclic loading and high cycle fatigue property of Ti-6Al-4V alloy was established by artificial neural network (ANN) modeling. The back propagation (BP) neural network and radial basis function (RBF) neural network were established by MATLAB. The input parameters of these models were the primary α volume fraction, primary α size, cyclic loading frequency and stress ratio. The output parameter was high cycle fatigue strength. The neural networks were trained with dataset collected from the literature. The prediction results showed that both of the networks have good generalization ability. In addition, the BP neural network with Levenberg-Merquardt (LM) learning algorithm has better fault tolerance and versatility in dealing with high cycle fatigue property, which is able to predict the high cycle fatigue property with a high accuracy.
Effect of Degree of Order on Hydrogen Diffusion in (Fe,Ni)3V Alloys
Authors: Chen Ye Xin , Hou Xi Bei , Chen Tao
Published: March 2016

The effect of hydrogen on the mechanical properties of disordered and ordered (Fe,Ni)3V alloys has been investigated. The diffusion behaviors of hydrogen in the disordered and ordered (Fe,Ni)3V alloys were reported. The results showed that the depth of intergranular (IG) fracture on a surface of tensile fracture of (Fe,Ni)3V alloy increased linearly with increasing pre-charging temperature at the same pre-charging time. An apparent hydrogen diffusion coefficient was calculated by the time lag method. The apparent hydrogen diffusion coefficient in the disordered (Fe,Ni)3V alloy was greater than that in the ordered (Fe,Ni)3V alloy. The relationship between the apparent hydrogen diffusion coefficient and pre-charging temperature in (Fe,Ni)3V alloy agreed with Arrhenius equation. The activation energies of apparent hydrogen diffusion in the disordered and ordered (Fe,Ni)3V alloys were 34.6 kJ/mol and 42.2 kJ/mo1, respectively.
Effect of Long-Term Aging on the Evolution of γ' and TCP Phases of a Ni3Al Based Single Crystal Superalloy
Authors: Zhou Xin , Xiao Jie , Pei Yan Ling , Li Shu Suo , Gong Sheng Kai
Published: March 2016

The coarsening behavior of γ' phase and precipitation behavior of TCP phase in a Ni3Al based single crystal superalloy were investigated by experimental and calculation. The Re-containing and Mo-rich single crystal superalloy used in this study exhibit good high-temperature strength and oxidation resistance. After fully heat-treated, the experimental superalloys were aged at 1050°C and 1150°C for different time periods from 50h to 1000h. The microstructure after thermal exposure was examined by field emission-scanning electron microscopy (FE-SEM). The results indicated that the coarsening behavior of γ' phase agrees well with the typical Lifshitz-Slyozov-Wagner (LSW) theory. After thermal exposure, both the size and the volume fraction of the TCP phase changed perceptibly.
Effects of Alloying Elements on the Properties of Ni-Mo-Cr Superalloys with Low Thermal Expansion
Authors: Yu Min , Cai Kai Hong , Li Zhen Rui
Published: March 2016

The effects of alloying elements including tungsten, molybdenum and cobalt on the thermal expansion and mechanical properties of Ni-Mo-Cr superalloys were investigated. It was founded that cobalt had no influence on the thermal expansion properties of the alloys. The addition of proper amount of tungsten reduced the coefficient of thermal expansion and increased the mechanical properties of alloy both at room temperature and at high temperature. Reducing the amount of molybdenum and increasing the amount of tungsten were helpful to reduce the coefficient of thermal expansion of the alloys at high temperature and improved the performance consistency of the coefficient of thermal expansion from low to high temperature.
Studies on Microstructure and Properties by Mass Smelting for Directionally Solidified Superalloy
Authors: Gao Yang , Niu Yong Ji , Shi Shi Feng , Tian Jian Jun , Wang Chao , Zhang Zhi Wei , An Ning
Published: March 2016

Large quantities of VIDP400 vacuum furnace smelting DZ417G oriented superalloys smelting process has been researched, analysis of the main factors affecting the organizational uniformity and stability, as well as the impact of high temperature tensile and lasting properties has been studied. The results showed that: At pulling rate of 4.5~8.5mm•min-1, after 1220°C solid solution treatment and 980°C aging system, the DZ417G superalloy had uniform chemical constitution with oxygen and nitrogen content of the alloy in sharply reduced to 13ppm. It can be got available treatment uniform structure with proper γ'phase size, with high-temperature tensile strength up to 750MPa, elongation of 17% reduction of area 22%. The lasting high temperature performance can reach to more than 100 hours.
Influence of Heat Treatment on the Microstructures and Mechanical Properties of K465 Superalloy
Authors: Huang Qiang , Song Jin Xia , Li Qing , Ren Wei Peng , Guan Xin Guang , Chen Hao
Published: March 2016

The microstructures and mechanical properties of superalloy K465 under different heat treatment, including as as-cast, solution treatment and aging, were investigated. The results showed that γ' precipitates in as-cast condition exhibited two kinds of morphologies of fine regular cuboidal shape at dendritic arm and coarse irregular form in interdendritic region. MC carbides decomposed into M6C carbides partly after 1210°C/4h solution treatment. The high temperature stress-rupture life can be improved obviously with the increasing cooling rate. When cooling rate was lower than 70°C/min, the room temperature tensile elongation increased with cooling rate increasing. When cooling rate was higher than 90°C/min the room temperature tensile elongation decreased with cooling rate increasing. The proper cooling rate of 70oC/min~90oC/min is advantageous for the achievement of excellent comprehensive properties. When aging treatments continued the regularization of γ' resulted in the improvement of stress-rupture life and the reduction of tensile elongation. The mechanical property gap between the solution treatment and aging can be decreased with increasing cooling rate.
Influence of Ti on the Microstructure and Performance of Fe-Cr Alloy Cladding Layer
Authors: Liu Jian Yang , Tao Qing , Lai Wei , Tang Wei Wei , Wang Jian , Liu Wei
Published: March 2016

Considering the multi-porous and rimous Fe-Cr series alloy coatings deposited on Q235 steel by plasma arc welding, the mass fraction of 0%, 2%, 4%, 6%, 8% Ti is mixed into Fe-Cr alloy powder. The microstructure and characteristics of the Fe-Cr series alloys with a range content of Ti were investigated using optical micrograph (OM), X-ray diffraction (XRD), scanning electron micrograph (SEM) Digital Micro-hardness Tester and M-2000 dry abrasion tester. The major phase of the Fe-Cr layers is dendrite with the lath carbide mixed between the limb of dendrite and the grains refine with addition of Ti. The XRD result indicates the main phases are (Fe-Cr) solution, Cr23C6, and TiC, while the result of Digital Micro-hardness test shows the microhardness increases with the mass fraction of Ti till it comes to 4% and decreases with the following addition of Ti. The highest average hardness of layer is 750HV with content of 4% Ti, while the coating with 2% Ti appears better wear resistance with the least wear volume for the match of toughness matrix and hard phase. Hence, the coating with 2% to 4% Ti shows the best property.
Modulation of Tribological Performance of Copper by Chemical Modification with H2O2/HCl Mixture
Authors: Cao Lei , Sun Zhuo Jun , Lin Hai Jun , Wan Yong , Gao Jian Guo
Published: March 2016

Tribological performance of materials is governed by their surface properties. The capacity to rationally design the surface physico-chemical cues of materials is thus a fundamental prerequisite to confer enhanced lubrication. The present study illustrated that the surface topological and chemical features on copper, which are expected to impact its tribological performance, can be easily modulated by varying the etchant’s concentration. The modified submicron and nanotextured surfaces on copper were characterized by scanning electron microscopy. Their tribological performance was evaluated by ball-on-disk tribometer measurements tester under both the dry and lubricating conditions.
Top-Down Fabrication of Superhydrophilic Graphene Oxide Nanosheets
Authors: Hu Xue Bing , Yu Yun , Ding Wen Xiou , Xiao Zhou Hao , Wang Yong Qing , Zhou Jian Er , Song Li Xin
Published: March 2016

As an oxidized form of graphene, graphene oxide has a variety of oxygen-containing groups together with a laminar structure, showing great potential in various engineering applications. In this work, on the basis of the top-down fabrication principle, superhydrophilic graphene oxide nanosheets with a uniform sheet size of ~50 nm diameter and 0.7 nm thickness were prepared by the modified Hummers method, and using microcrystalline graphite as the carbon source. After chemical oxidation, the obtained graphene oxide nanosheets had a great amount of C-O-C, C-OH and C=O groups and its water contact angle was ~3.9°. This result offers a facile strategy to fabricate superhydrophilic and monolayer graphene oxide nanosheets with well-defined morphology.
Feasibility of FRP as the Oil and Gas Long-Distance Pipeline Material in the Area with the High Voltage Electric-Power Line
Authors: Wang Jiang Yu , Sun Xiao Jie , Zhang Mi , Wu Sha , Zhang Zhi Yu
Published: March 2016

Oil and gas long-distance pipelines which are buried under ground often have to be closely laid in the narrow area with the high voltage electric-power line. The earth electrode of the electric tower seriously impacts the cathodic protection system of the pipeline when it discharges electricity into the earth. Sometimes the cathodic protection system may even lose its efficacy and the pipe being corroded. Under this condition, fiber reinforced plastics (FRP) has been paid more and more attention as the alterative of the steel pipe because of its outstanding cathodic-resisting property. In this article, the property of FRP compared with the steel was analyzed. The advantages and shortcomings of FRP as the material of oil and gas long-distance pipeline were introduced. Furthermore the feasibility of FRP pipeline was discussed.
Effect of Ferrous Ion on the Corrosion Behaviour of 410 Stainless Steel in Wet H2S Environment
Authors: Zhou Jie , Bai Peng Peng , Wang Tian Qi , Zheng Shu Qi
Published: March 2016

In this paper, the effect of ferrous ion on the corrosion behavior of 410 martensitic stainless (410SS) steel was investigated by corrosion tests, scanning electron microscopy (SEM) and X-ray diffraction (XRD). The corrosion tests were conducted in brine solution saturated with H2S and two type of iron compounds (FeS and FeSO4). The reults revealed that there exists apparent difference between piting resistence of FeSO4 and FeS addition for 410SS. The corrosion rates of specimens in FeSO4 solution was much higher than that of FeS, and the corrosion rate reached a maximum of 1.299 mm/year when the concentration was about 0.15 mol/L. The SEM results showed that without FeS (indissolvable) and FeSO4, steel suffered slight corrosion, meanwhile several pittings appeared after 42 h. Compared with that of FeS, much more pittings grew on the specimens with FeSO4. The corrosion product was mainly mackinawite.
Effect of Heat Treatment on the Microstructure and Mechanical Property of x90 Bend Pipe
Authors: Wang Bin , Wang Liang , Lei Bo Bo , Xu Ming
Published: March 2016

The microstructure and mechanical property of X90 parent material and weld were studied after the heat process of tempering (560°C) and quench (1000°C) + tempering (560°C), respectively. By the comparison of two different heat treatment processes, the effect of heat treatment for the microstructure and mechanical property of X90 parent material and weld was discussed. The results shown that the weld and heat-affected zone (HAZ) microstructure was improved after the heat process of quench (1000°C) + tempering (560°C), and the microstructure of HAZ was refined, which make the microstructure and mechanical property of X90 bend pipe parent and weld more similar, effectively. In addition, this paper also proved that the entire heating mode can effectively reduce the deterioration of microstructure and mechanical property caused by the bending process.
Effect of Thermal Aging on Migration Characteristics of Heavy Metal in PET
Authors: Song Xiao Yun , Sun Zhuo Jun , Li Chun Ping , Gao Jian , Ma Jing Long , Guo Bing , Zhao Fu Wen , Yu Hong Guan , Gao Jian Guo
Published: March 2016

Polyethylene terephthalate (PET) is usually used as food packaging materials. And the heavy metal introduced during the process of manufacture usually exists in the spaces between macromolecules as monomer form. When PET contacts with real food, some heavy metals will migrate into the food since the motion of these molecules overcomes the binding power. As a result, it does great harm to our health. In this article PET was disposed in different thermal ageing conditions in order to accelerate its aging process. Then the original and aged PET samples were tested by Different Scanning Calorimeter (DSC) to characterize its crystallinity. And migration experiments was conducted on them using 4% acetic acid (V/V) as food simulate, the heavy metal content in food simulates was detected by Inductively Coupled Plasma Mass Spectrometry (ICP-MS), so that we can get the migration characteristics of heavy metal. The results show that different aging conditions can do harm to the structure of PET in varying degrees by changing its crystallinity and molecules arrangement. But the difference of crystallinity has no obvious effect on Sb migration characteristic of PET samples. While, the migration quantity of Sb increases significantly with the increase of migrate temperature. It will provide an important reference to the evaluation of use security and service life of PET in real usage to study the relation between heavy metal migration features and aging degree.
A Non-Contact Test Method on Local Mechanical Properties of Weld Joint
Authors: Song Ming , Wang Hui , Xu Tong , Zhang Xue Tao , Xiang Jing , Sun Yong Hui , Shou Bin An
Published: March 2016

A comprehensive study was carried out on the determination of mechanical parameters in the weld zone by using the digital image correlation (DIC) method. The DIC method provided quantitative two-dimensional strain maps of the deformation field across the weld joint throughout the tensile test. Then the local stress-strain response was extracted based on these strain maps on the uniform stress hypothesis. The strain distribution evolution during loading performed a good consistency with the indentation test results and the cracking position of the specimen. The deformation related parameters of local areas in weld joint were successfully extracted by DIC method. These parameters are very valuable for the structure design of the weld components, especially in the case of the structure in which the allowable stress is controlled by the deformation feature but not the strength of the material such as the high temperature applications.
Atomistic Study of the Copper Cluster Deposition on Si(001) and Si(111) Surface
Authors: Gong Heng Feng , Li Gong Ping , Zhang Shi Xu , Lu Wei , Wang Lu Min
Published: March 2016

The deposition of a single Cu cluster on the Si (001) and Si (111) surfaces was studied by molecular dynamics simulations. EAM, SW and Morse potentials were used to describe the interaction of Cu-Cu, Si-Si, and the Cu-Si atoms, respectively. The results show that the crystallographic surface of the substrate had a large effect on film growth. On the Si (111) surface, the cluster structure demonstrate good uniformity and epitaxial relation to the substrate. There is no appreciable intermixing or silicide formation at the film-substrate interface, nor silicon segregation on the surface with incident energy between 0.1 and 1.0eV/atom. However, as the incident energy increases to 3.0eV/atom, intermixing began to appear for Cu13 and Cu19 clusters. For the Cu147 cluster intermixing starts to appear at a lower energy of 1.6eV/atom. In contrast, intermixing appears on the Si (001) surface for a range of incident energy from 0.1 to 3.0eV/atom for all the three clusters studied. Furthermore, the epitaxial relation with the Si substrate result in (001)- or (111)-oriented Cu clusters on Si (001) or Si (111), respectively. This behavior is consistent with experimental observations. We found that the effect of cluster deposition on film property depends not only on the substrate-film material combination and cluster size but also on the substrate crystallographic orientation and incident energy.
X-Ray Powder Diffraction Data and Crystal Refinement of a New Compound AlCrNi3Pr
Authors: Liu Shu Hui , Liang Liu Qing , Qin Chang Sheng , Li De Gui , Zeng Ling Min , He Bin
Published: March 2016

Rare earth-transition metal (R-T) intermetallics have been well used because of their excellent properties. The X-ray diffraction patterns of many new phases in the R-T system have not been extensively studied. A new compound AlCrNi3Pr was prepared by arc melting using non-consumable tungsten electrode under argon atmosphere, and then annealed at 1023K for 30 days. The X-ray powder diffraction data of AlCrNi3Pr was collected on a Rigaku SmartLab X-ray powder diffractometer. The powder patterns of the compound were indexed, and the structure refinement by using Rietveld method indicated that the AlCrNi3Pr compound crystallized in the hexagonal structure, space group P6/mmm (No.191) with PrNi5 structure type, a=b=5.0553(9) Ǻ, c=4.0763(6) Ǻ, V=90.22Ǻ3, Z=1, ρx=7.288g cm-3, the Smith–Snyder FOM F30=279.1(0.0044, 32) and the intensity ratio RIR=1.23.
Correlation between the Local Melt Structure and the Dynamical Properties of Mn, Zn and Si in Liquid Al: An Ab Initio Molecular Dynamics Study
Authors: Yang Jian , Zhang Jiao , Dai Yong Bing , Ma Jian Bo , Sun Bao De
Published: March 2016

In this study, Mn, Zn and Si elements which are the most common alloying elements in Al, were chosen as solute atoms to be analyzed. The structure of molten Al, local structure around solute atoms and diffusion of the solute atoms are studied using ab initio molecular dynamics simulations. The results show that minimum addition of a solute (1 atom) does not significantly influence the structure of liquid Al as a whole. However, the local structure around foreign atoms varies dramatically for the different solute species. The local structure around Mn is the most compact and stable among the three types of solute atoms, leading to its lower diffusion coefficient. Conversely, Si possess the highest diffusion coefficient among those three kinds of elements derive from the local structure around Si is the most relaxed structure. In summary, the close packing and stable spherical shell around the solute atoms affect their diffusion behaviors in the melt. In addition, it is suggested that more alloying elements should be investigated to corroborate the results of this study.
Prediction of Melt Flow Effects on Dendrite Growth
Authors: Chen Yun , Qi Xin Bo , Li Dian Zhong , Kang Xiu Hong
Published: March 2016

The effects of melt flow on dendrite growth during solidification are studied by the quantitative phase field model coupling the Navier-Stokes equations. Through analyzing the relationship between flow velocity and dendrite growth rate in simulations, a flow Péclet number involving with characteristic flow velocity, characteristic length of the zone affected by flow and thermal (solute) diffusion coefficient, is suggested for dendrite growth under convections. The growth rate increment due to flow follows a power-law relationship with the Péclet number. As the Péclet number is much higher than one, the influence of convection on dendrite growth is apparent, whereas as it is below one, the flow effects can be neglected.
DFT Study of Chemisorbed Atomic Oxygen Inducing Co Segregation in CoNi(111) Alloy
Authors: Yu Yan Lin , Wang Li Gen , Xiao Wei , Huang Guo Jie
Published: March 2016

Chemisorbed atomic oxygen inducing Co segregation in CoNi (111) alloy is studied using periodic self-consistent density functional theory (DFT) calculations. In particular, the coverage dependence and possible adsorption-induced segregation phenomena are addressed by investigating segregation energies (the difference in calculated total free energy between surface sites and bulk-like sites) of isolated Co in CoNi (111) alloy. In agreement with previous experimental and theoretical investigations, segregation of Co is found to be oxygen-coverage dependent. While for ‘clean’ CoNi (111), Co prefers to be in the bulk. In the presence of more than 2/9 ML of oxygen, Co segregates to the surface. The analysis of oxygen adsorption trends and surface electronic structures explains the change in the local atomic arrangement which is expected to occur on the surface of alloys under reaction conditions. Our predictions for the high oxygen coverage cases are particularly relevant in underlining the importance of segregation phenomena to the hydrogen evolution performance of CoNi alloy hydrogen evolution electrode.
Fracture Toughness Analysis of the China RPV Steel with Miniaturized Specimen
Authors: Lin Yun , Yang Wen , Tong Zhen Feng , Ning Guang Sheng
Published: March 2016

Reactor pressurized vessel (RPV), which determines the lifetime of the nuclear power plant (NPP), is mainly forged using A508-3 steel in China. In order to meet the requirement of the small specimen test technique in the nuclear application, the fracture toughness of A508-3 steel was tested under-100°C using 1/4 CT specimens, and analyzed using Master Curve according to ASTM E 1921. In this work, the relationship of the KIC and the distance between the cleavage crack initiation site and the front of the fatigue crack is studied, and the transition temperature T0 of A508-3 is-98.7 oC, which is quite close to the test temperature.
Thermodynamic Calculation of Bi-Au-Lu, Nd Ternary Systems
Authors: Wang Shu Liang , Zhou Lu Jiang , Li Jia Lian , Wang Xiao Hong , Lin Yuan Hua , Liu Xing Jun
Published: March 2016

With available melting point and hardness, the Bi-based filler alloy is considered as one choice of high-temperature Pb-free solder. Phase diagram can play an important role in the design of new type of Pb-free solder.In the present work, the thermodynamic assessments of the Au-Nd and the Au-Lu binary systems have been carried out by the Calculation of Phase Diagram (CALPHAD) method based on the available experimental data. The Gibbs free energies of the solution phases were described by subregular solution models with the Redlich-Kister equation, and those of the intermetallic compounds were described by sublattice models. A set of self-consistent and reasonable thermodynamic parameters is obtained for the binary systems, which describes the Gibbs energies of the solution phases and the intermetallic compounds phases. Additionally, combined the reported Bi-Au, Bi-Lu and Bi-Nd binary systems, the thermodynamic database of the Bi-Au-Lu and the Bi-Au-Nd ternary systems have been developed, which will provide important thermodynamic information for the phase equilibria of the multicomponent Bi-based alloy systems.
Development of Cooling Process Control System for Backward UFC in CSP
Authors: Li Xu Dong , Yuan Guo , Li Zhen Lei , Zhang Zhao Peng , Cao Xin Li , Wang Guo Dong
Published: March 2016

Backward Ultra-fast cooling (UFC) plays a key role in low-cost dual-phase steels production. Cooling process control system for backward UFC was developed to meet the process requirements. Basing on basic theory of heat transfer, cooling control model was established to accomplish temperature calculation. To deal with the influence of technological conditions fluctuations an adaption system, including self-learning function and feedback function was proposed to intelligently realize temperature correction. The developed cooling strategy can achieve diversified cooling path control. The controlling of significant technological parameters, including cooling rate and air cooling time for dual-phase steels, was also accomplished. Furthermore, flexible and diversified UFC strategies were developed aiming at high temperature precision and low temperature deviation control in thickness direction. The system has been applied successfully in dual-phase steel production with high stability and reliability. The precision of medium temperature (MT) can be controlled within ±10°C, and the UFC delivery temperature (UFC-T) can be limited within ±30°C of the target values.
Numerical Analysis on the Density Uniformity for SiCp/2024Al in the Extrusion Process
Authors: Wang Yan Ju , Chu De Sheng , Tang Peng Jun , Guan Yong Jun
Published: March 2016

Many factors can influence the density uniformity of the SiC particle reinforced aluminum matrix composites, including the material preparation method and the material processing technology. The influence factors on the density uniformity of SiCp/2024Al in the extrusion process were studied in the present investigation. Those factors contain the extrusion ratio, the extrusion velocity, the temperature and the friction coefficient. The flow stress of this material under different temperatures and strain velocities was tested by heat physical simulation experiments. As a result, the true stress-strain curve was obtained and the phenomenological constitutive equation was established, and the FEM simulation was used for the extrusion process. The velocity gradient computed by the numerical simulation was used to describe the density uniformity. The density uniformity caused by different extrusion process parameters was compared and analyzed. The results showed that the density uniformity was improved obviously by the optimization of extrusion process parameters. At last, the real extrusion process test was organized to verify the numerical simulation results and the most suitable characteristic parameters of the extrusion mold and the process was finally determined.
Effect of Magnesium Content on Machinability of Cu-Zn-Bi-Sb Alloy
Authors: Gan Chun Lei , Zheng Kai Hong , Wang Hai Yan , Zhou Nan
Published: March 2016

In order to develop high-performance lead-free brasses, the effect of magnesium content on the machinability of lead-free brass alloys was carefully studied in the present work. The ingots of the Cu-Zn-Bi-Sb alloy were fabricated in terms of different magnesium contents of 1.0, 2.0, 3.0 and 4.0 wt%. The difference in the machinability of the Cu-Zn-Bi-Sb alloy ingots was discussed in terms of their microstructure, mechanical properties and chip morphologies. X-ray diffraction analysis indicated that α phase (0~38 Zn by atom %), β phase (45~49 Zn by atom %), CuMgSb and CuMgZn existed in the Cu-Zn-Bi-Sb alloys with the different magnesium contents. With increasing the content of magnesium, the machinability of the present lead-free brass alloys was markedly improved, which is mainly attributed to the formation of intermetallic compounds such as CuMgSb and CuMgZn.
Effect of Cooling Rate on Microstructure and Mechanical Property of Fe-6.5wt%Si Alloy
Authors: Jiao Jing Ye , Shen Qi Zhao , Cheng Ai Chao , Guo Ren Fei , Zhou Tie Tao
Published: March 2016

Due to its high silicon content, Fe-6.5wt%Si alloy has low iron loss and its magnetostriction is almost zero. And therefore Fe-6.5wt%Si alloy has good development prospect. However it has poor ambient temperature ductility and its cold rolling is very difficult. It’s important to study the effect of cooling rate on the microstructure and mechanical properties of Fe-6.5wt%Si alloy. In the present study the master alloy was melted and cooled through normalization, gas atomization, laser surface remelting and melt spinning. The microstructure, micro-hardness and X-ray diffraction were analyzed. The evolution of the microstructure at different cooling rate was summarized. The results indicated that under high cooling rate, the grain was obviously refined, and the microhardness decreased, but the change of phase was not obvious.
Study on Grain Refinement and Homogenization of Large-Sized DC Casting Ingot by A-EMS Melt Treatment
Authors: Luo Ya Jun , Zhang Zhi Feng , Gao Ming Wei , Xu Jun , Zhang Shao Ming
Published: March 2016

Electromagnetic stirring (EMS) process, as an advanced melt treatment technology, is increasingly applied in metallurgy industry. Direct chill (DC) casting process by annular electromagnetic stirring (A-EMS) was applied in this study to investigate the solidification behavior of a modified 7N01 alloy, and the effects of DC casting process without EMS, and A-EMS casting process on microstructure, composition segregation and mechanical properties of continuously cast billets were compared. The research results showed that the billets with higher performance, lower macro-segregation, more uniformly fine solidification structure were obtained in case of A-EMS.
Elements Diffusion and Mechanical Properties of 15-5PH Stainless Steel Joint Brazed with BNi-2 Filler Metal
Authors: Sun Qian Qian , Lu Sheng
Published: March 2016

The effects of brazing time on elements diffusion and bonding strength of vacuum brazed joints of 15-5PH stainless steel using filler metal BNi-2 were investigated. The results showed that the brazing time determined the content of diffused elements. If holding time is short the distribution of melting point depressants (MPD) concentrated on the middle zone of the joint, and the generation of brittle phases in the joint was unavoidable. With increasing time, MPD can diffuse to base metal adequately and full solid solution of nickel formed in the brazing joint. Joint strength firstly increased and then decreased with prolonging holding time.
Investigations of Microstructure and Phase Composition of Different Self-Shield Flux-Cored Wire Slag System
Authors: Yi Jiang Long , Wang Xin Xin , Wang Kai , Zheng Shi Da , Chen He Xin , Guo Chun Fu , Niu Ben
Published: March 2016

A series of slag were fabricated by self-shield welding of different flux-cored wire. The microstructure and phase composition of those slag were investigated by means of metallographic microscope, SEM,EDX and X-ray diffraction respectively. The result demonstrated that the slag forming material of TiO2 and Al2O3 tenders to form the framework structure of slag, while CaO and MnO2 inclines to incorporate in the grain boundary. Furthermore, the dense and dendrite phase structure of slag was beneficial for the removal of slag. On the contrary the slag with tiny needle and skeleton-like structure was difficult to clear up. In conclusion, the detachability performance was not only affected by the microstructure, but also by the chemical composition of the slag system.
Genetic Characteristics and Mechanical Properties of High-Siliconaluminum Alloy by Rapid Solidification and Spark Plasma Sintering
Authors: Zhang Xiao Dong , Chi Yue , Zhao Zhan Kui
Published: March 2016

High-silicon aluminum alloys as light-weight structural materials are attractive because of their high wear resistance, low density and low thermal expansion. However, the Si phase in the high-silicon aluminum alloys always has big size, which deteriorates the mechanical properties and machinability of alloys. In this paper, alloy ribbon of high-silicon aluminum alloy with the composition of Al70Si30 was prepared by melt-spinning method. Then alloy ribbon was broken to powder by ball milling. The alloy powers were consolidated by spark plasma sintering (SPS) at different sintering parameters including time and temperature under vacuum atmosphere. The density, hardness and compression property of the compacts were investigated. The sintered samples were characterized by scanning electron microscopy (SEM) and X-ray diffractometry (XRD), and compared with their alloy power and original alloy ribbons. The results showed that the density of Al70Si30 alloy, prepared under the condition of 320 °C and 500 MPa, was above 98%, the grain size was refined to sub-micron, and the wear resistance was good, micro-hardness was 311.70 Hv. It is believed that the existence of local high temperature and discharge plasma can break down and disrupt oxidation film on powder surface, and therefore improving the efficiency of sintering. In the case of large current, short time and low temperature, sintering grain growth was not obvious, there was less supersaturated solid solution precipitation and the rapid solidification microstructure , and the properties can be preferably reserved.
Numerical and Experimental Study of Temperature Rise Effect on Copper during Equal Channel Angular Pressing
Authors: Guo Ting Biao , Cao Jun , Ding Yu Tian , Jia Zhi
Published: March 2016

The temperature rising of pure copper during equal channel angular pressing (ECAP) was investigated based on the soft DEFORM 3D. The simulation results were compared with test results, and the microstructure evolution and recrystallization process was analyzed. The experimental results showed that under the same deformation conditions, different initial states of materials had different deformation temperature raised, with which the strain state further affected the recrystallization process. In the certain scope of die channel angle, it will have an optimal grainrefinement effect. As strain increased, the material microstructure engendered a non-equilibrium structure at the macro level, and recrystallization became complicated. Control ECAP deformation parameters had an observable effect on grain refinement. After plastic deformation, the parameters of the material’s state, die structure and deformation temperature determined the material’s grain size limit. The simulated results agreed well with the experimental results.
Engineering Critical Assessment for the Flaws in the Pipeline Steel Girth Weld
Authors: Wu Jiang Qiao , Yao Deng Zun , Yuan Xin Ran , Wang Tian Qi , Zhang Long
Published: March 2016

In the pipeline construction, the girth welds tend to be the weakness because of defects and microstructure. The importance of suitable assessment of various defects in the weld is not only to prevent the cracks from unstable growth to cause catastrophic accident but also can effectively reduce the weld repair to reduce construction cost. Although many welding defects assessment methods and codes are used in this field, there are many differences among them. In this paper, the welding defect assessment methods, such as API 1104 and BS7910, were studied. The results show the key factors that affect the result of these assessment methods. The application of these methods was also discussed. The results indicate that API 1104 level1 has the highest conservatism, while API 1104 level 2 is next.
Water Absorption of Polyethylene Heat-Shrinkable Tape
Authors: Sheng Qing Nan , Ye Chun Yan , Guo Xiao Jiang , Li Ye Zheng , Liu Tong
Published: March 2016

In this paper the water absorption properties of polyethylene shrink tape were analyzed for long-distance pipeline. In the water absorption experiments, the normal and high temperature type heat shrinkable tape from six different manufacturers were respectively immersed in water range from 24 h to 28 d. The results show that the water absorption of the normal and high temperature type heat shrinkable tape was steady under the condition of 144 h. Once exceeding 144h, the water absorption increased gradually. Furthermore, the glue layer of heat shrinkable tape had a greater impact on water absorption. And the water absorption of glue layer of heat shrinkable tape decreased with an increase of the hot glue layer thickness,
Contrastive Study on Finite Element Models of High-Strength Pipelines Crossing Active Faults
Authors: Zheng Wei , Zhang Hong , Liu Xiao Ben , Liang Le Cai , Han Yin Shan
Published: March 2016

There is a potential for major damage to the pipelines crossing faults, therefore the strain-based design method is essential for the design of buried pipelines. Finite element models based on soil springs which are able to accurately predict pipelines’ responses to such faulting are recommended by some international guidelines. In this paper, a comparative analysis was carried out among four widely used models (beam element model; shell element model with fixed boundary; shell element model with beam coupled; shell element model with equivalent boundary) in two aspects: differences of results and the efficiency of calculation. The results show that the maximum and minimum strains of models coincided with each other under allowable strain and the calculation efficiency of beam element model was the highest. Besides, the shell element model with beam coupled or equivalent boundary provided the reasonable results and the calculation efficiency of them were higher than the one with fixed boundary. In addition, shell element model with beam coupled had a broader applicability.
Analysis of N80 Tubing Failure for CBM Well Drainage
Authors: Qu Wen Tao , Sun Xu Guang , Gou Jian Sheng , Tang Feng Ling
Published: March 2016

Aimed at the serious problem of N80 tubing failure in the drainage of CBM (Coal bed methane) well, it can define the failure into two types: eccentric failure wear and the corrosion failure, through analyzing the well space structure, the stress and the chemical reaction on the tube in the coal bed water. The main reason is well deviation, instability of rod string and rod vibration. It makes sucker rod contacts with the N80 tube, when the sucker rod is up and down, the friction exists between the sucker rod and the tube, which leads to the tube wear out. Corrosion failure may happened in the condition that there are some acid anions in the coal seam water, such as HS-, S2-, Cl-, HCO3-, SO42-, CO32-, etc. These ions react with N80 tubing that corrodes and destroys the N80 tube. In this paper, we suggest to replace the N80 tube with the UHMWPE (ultra-high molecular weight polyethylene) liner tube. This is capable to reduce the wear and corrosion rate effectively. The field tests show that it is still useful over 600 days, which means that the serving life of UHMWPE liner tube can be increased over 50 percent than others. Therefore, it has a significant meaning to popularize UHMWPE liner tube in the CBM well.
Active Casing Controlled with a Partial-Update Neural Network
Authors: Kurczyk Sebastian , Pawelczyk Marek
Published: March 2016

An active casing made of appropriately controlled vibrating plates can be used to reduce noise propagating from the mechanism enclosed in the casing. Since a practical vibrating casing can behave in a nonlinear way, the performance quality strongly depends on the ability of control filters to compensate for the nonlinearity. The classical approach to nonlinear active control, e.g. based on the Volterra filters, can deal with harmonics generated by the nonlinearity. However, when a complex structure is considered, neural networks have a higher potential. Although, they are much more computationally demanding, for some cases they can be simplified and still provide acceptable performance.In this paper, results of control obtained for a real casing with multiple actuators exciting each wall are presented and discussed.
Balance Maintaining by Human
Authors: Kot Andrzej , Nawrocka Agata
Published: March 2016

Harmonious cooperation of the skeletal, muscular and nervous systems, forming a human motion organ, is responsible for all undertaken movement activities. Motion organ in the illustrated embodiment responsible not only for two basic motion activities, locomotion and manipulation, but also for maintaining the posture of the human body. Standing posture control makes a particular dimension of physical activity, because correct, stable posture determines the ability to perform most human movements. In the case of a man to maintain a balance in a standing position seems to be something obvious and does not require much effort, but with the advent of lesions or aging we begin to see how complex it is the process of balance control. The changes lead to impaired balance control which in turn can lead to the appearance of postural instability and in extreme circumstances, even to collapse. Maintaining a stable posture it is primarily associated with motor control provided by the human nervous system. The nervous system acts as an posture control system and most of all giving to a body well-defined silhouette. This control relies heavily on the integration of information from the human receptor system. Muscle, joint, tendon and skin receptors communicate first to the brain information about the movement and position of individual body parts and then feedback these signals to the muscles, causing reflex reactions allowing for correction of posture and thus return the center of gravity to a position that maintaining equilibrium. Subdivide those human body into segments linked closely with the system osteoarthritis limbs and trunk can create a system of interconnected pendulums with many degrees of freedom. In the case of standing it will be largely complicated inverted pendulums system by which activities phenomena associated with maintaining balance and locomotion can be modeled. If additionally in an upright position, taking into account the natural motion restrictions movements in all joints except the ankles will be blocked, the body will be a close approximation behave like a rigid body. So we can assume that for supporting the human body at the ankle, it will behave like an inverted pendulum. The article presents the ways of describing the equilibrium of man as an inverted pendulum.
Experimental and Simulation Investigations of the Cantilever Beam Energy Harvester
Authors: Nowak Radosław , Pietrzakowski Marek
Published: March 2016

Machines, cars suspensions, buildings steel constructions etc. usually generate vibrations, which can be the excitement signal for piezoelectric energy harvesters. The piezoelectric patches attached to the vibrating construction have ability to convert mechanical energy of harmful vibrations into electrical energy.The goal of the study was to verify a finite element model of the piezoelectric beam energy harvester by comparing results of numerical simulations with those obtained experimentally. The stand used in the experiment consists of the cantilever beam with piezoelectric elements attached, which is excited by the base harmonic movement. The transverse displacements of the selected beam’s point and the base, and also the frequency of vibrations were observed and measured using an accelerometer and a B&K Pulse platform. A portable data acquisition module was used to quantify the voltage generated by the piezoelectric layers.The finite element model was built in ANSYS software. The beam and piezoelectric layers were modeled by twenty node elements with an additional electric degree of freedom for piezoelectric elements. A full piezoelectric matrix was used in the finite element analysis instead of a one-dimensional piezoelectric effect, which dominates in many analytical approaches. It allowed building a more accurate model of the system. The experimental tests and finite element method simulations were performed and acquired results were compared. The characteristics of voltage amplitude in the time and frequency domain were shown and discussed.
A Higher-Order Spectra Based Method of On-Line Secondary Path Model Identification for Active Noise Control Systems
Authors: Główka Teresa , Figwer Jarosław
Published: March 2016

The aim of this paper is to present a method of nonparametric and parametric secondary path model identification for adaptive active noise control systems with low-power non-Gaussian excitations of the form of a higher-order discrete-time multisine random process and data processing based on cross-higher-order spectra. Properties of the discussed method are illustrated by simulation experiments devoted to secondary path identification for feedforward and feedback active noise control systems. Its robustness to nonlinear distortions implied by data acquisition system and adaptation procedure is proved.
Liwan Field Development: The First Deepwater Gas Field in China
Authors: Fu Yamei , Gong William , Li Li , Su Rui , Wei Fang
Published: March 2016

LW3-1 gas field is located approximately 310 km southeast of Hong Kong in water depths ranging from 1300 to 1500m. It was first discovered in August 2006. The development of this field aims to achieve optimum recovery factor by concurrent depletion strategy and meet the peak gas nomination of downstream demand. This paper is to present the philosophy and methods used in the overall development plan and the practices during the field production period.

LW3-1 has developed 3 main sands with 9 subsea directional wells including two appraisal wells. Each well has been perforated in single sand to avoid interference among the sands through the wellbore. Balanced depletion strategy has been used to optimize ultimate recovery factor, which was estimated by reservoir simulation, analogue and empirical methods for this field. Before all the wells were put on line, the clean-up operation was carried out to determine the well deliverability after completion. LW3-1 first gas was on March 31, 2014, almost 8 years after its discovery.

The reservoir and production teams have worked closely to generate and implement the initial start-up procedures to meet flow assurance and safety requirements. In order to monitor reservoir and production performance, two down-hole gauges and wet gas flow-meters were installed in each well. A real time production surveillance system and database have been also set up to help efficient reservoir management. The actual reservoir and production data so far has met the expectations in the overall development plan. Good communications within Sand 1 and between Sand 2 and Sand 3 have been observed.

LW3-1 is the first deepwater gas field in China and this paper provides valuable information and experiences of the reservoir management and production monitoring of this field.
De-Risking Drilling Campaign from Geohazards and Overpressured Reservoirs - A Case Study
Authors: Vijapurapu S. , Chong Cindy. K. S. , Lee E. E. , Warrlich Georg M. D. , Mukhopadhyay A.
Published: March 2016

This paper describes the approach of an integrated team of Subsurface and Well Engineers to mitigate the substantial technical risks of a 3-well field development in offshore Sarawak, Malaysia. These challenges ranged from significant geohazard risks in the overburden to uncertainties regarding the extent of potential overpressure in the reservoir section.

The overpressure prediction in the reservoir section arose from detailed analysis of previous exploration and appraisal well abandonments, which indicated the potential for cross-flow from highly pressured sands in the under-burden.

To de-risk the execution phase of this campaign, a multi-disciplinary team of subsurface and well engineers focused on the following key factors: –Evidence for drilling hazards in offset wells–Evidence for cross-flow from deeper high pressured sands into the reservoir section–Geohazards identification in the overburden section–Data acquisition & real time monitoring–Pore pressure prediction–Mud-weight management–Integrated casing design–Hard-stop TD criteria for each well section–A range of "What-if Scenarios" that covered risk identification & mitigation

The well designs eventually selected for this development included both low angle (~40 deg inclination) and extended reach wells (~70 deg inclination) drilled to a target depth of some 21,000 ft.

The successful outcome of this challenging campaign can be attributed to good team integration, rigorous assessment of the risks based on all the available data, and excellent communication and co-operation between the office and rig during operations.

The team created "Well Trouble Plots" for every development well which summarizes the information regarding events such as losses, geohazards and mud weight from the offset wells.