bluuebunny/crossref_metadata_2025 huggingface dataset:
Workspace Analysis of a 6-DOF Installing-Calibrating Robot
Authors: Xie Zhi Jiang , Li Cheng , Ni Wei , Liu Nan
Published: December 2011

According to the working characteristics and installment environments of modules，a compact 6-DOF installing-calibrating robot was designed. Coordinate systems of joints are set upand the forward kinematic solution are derived by using D-H methods. Using the Monte Carlo method based on random probability and MATLAB software simulation for the robot's structural parameters to the robot's workspace impact. According to joint space to the mapping workspace，robots have been the workspace. The research results have proved that the designed configuration can satisfy the needs of installment action，which will provide theoretical reference for the robot trajectory planning，dynamic analysis and online real-time calculation.
Wear Research and Improvement Design of Slipper Pair in Axial Piston Hydraulic Motor Lubricated with High Water Based Fluid
Authors: Gu Yong Xia , Zhou Zhong Ning , Gao Fei
Published: December 2011

The flow field of lubrication film under the bottom of the slipper is analyzed particularly. The velocity in different points of the lubrication film on the bottom of the slipper is solved based on the premise that the rotation and self-rotation of the slipper has been taken into account of. This paper puts forward that regular concaves converging along the radial direction be set up in the cyclic zone of slipper’s bottom surface to enhance the lubrication effect and improve the overwear situation in the peripheral parts of the slipper.
Research on Automatic Positioning System in Traffic Accident
Authors: Guan Zhi Guang , Liang Jie , Miao Qiu Hua
Published: December 2011

With the rapid development of the global economy, automobile industry and high-grade highway create the necessary tools and infrastructure for the fast and convenient traffic. However, the cars also bring some negative effects of human life, such as traffic accidents. China has become the world's most serious national in the traffic accidents. In order to make the traffic accident rescue convenient, the automatic positioning system is studied, and the software and hardware are also designed. The control system uses the PIC18F458 as a controller, which combines with the modern sensor technology and GPS, and realizes the automatic positioning in traffic accidents. Experiments show that the system has the advantages of stability, reliability and strong anti-interference ability.
Preliminary Study of Human Factor Reliability in Hydropower Station
Authors: Li Dan Dan , Li Lei
Published: December 2011

Now human error has caused lots of accidents of hydropower station home and abroad, but there is no direct method to calculate the probability of human error in accidents of hydropower station. So the paper invite the suggestion of introducing the human reliability into hydropower station risk analysis, which can perfect the hydropower station risk theory. It used improved HCR(Human Cognitive Reliability) method to calculate human reliability of hydropower station , but the concrete parameters need further research combined with engineering practice.
Optimization Design of MW-Class Wind Turbine Gear Transmission System Based on MATLAB and SQP Algorithm
Authors: Lan Fei , Liu Kai , Ma Chao Feng
Published: December 2011

This paper introduces the principle of the SQP algorithm and how to realize in MATLAB optimization toolbox. With mega watt wind turbine gear transmission system as the research object, the selection of the appropriate design variables and constraints, as the volume of transmission system is the smallest and part of the gear rotational inertia minimum for target function, and set up the optimization mathematical model. Use the MATLAB optimization toolbox to optimize, and then calculate and analysis the example. The results show that before and after the optimization of the system, the volume and the rotational inertia of the gear are significantly reduced. This paper will supply some references for the wind power gear transmission system design.
Microstructural Investigation of Co-Rolled Nanocrystalline Stainless Steel Sheets
Authors: Retraint Delphine , Quadir M. Zakaria , Xu Wan Qiang , Waltz Laurent , Ferry Michael
Published: December 2011

It is possible to produce a nanocrystalline, multilayered composite structure with enhanced mechanical properties by assembling three 316L surface nanostructured stainless steel plates by roll bonding. The Surface Mechanical Attrition Treatment (SMAT) was first used to generate nanocrystalline layers on the elementary plates so that their mechanical properties were improved. They were then assembled through co-rolling. A composite structure of nanocrystalline layers of high strength alternating with more ductile layers was obtained to achieve both high strength and ductility. Microscopy observations and EBSD measurements were carried out and the bonding interfaces were analysed in detail to explore the mechanisms involved during the SMAT/Co-rolling duplex process.
Texture Evolution of HPT-Processed Ni50Mn29Ga21
Authors: Chulist Robert , Böhm Andrea , Rybacki E. , Lippmann T. , Oertel C.G. , Skrotzki Werner
Published: December 2011

The texture of polycrystalline Ni50Mn29Ga21 alloys fabricated by high pressure torsion (HPT) was investigated with high-energy synchrotron radiation. HPT was performed at temperatures between 873K and 1173K under a hydrostatic pressure of 400 MPa. During HPT above 973K the initial cyclic fibre texture changes to a strong cube and a weak F component. Below 973K a strong rotated cube and weak F and C components develop. Additionally, electron backscatter diffraction reveals that samples deformed at low temperature do not completely transform to martensite giving rise to residual austenite.
Textures in Industrial Processes and Products
Authors: Hirsch Jürgen
Published: December 2011

Textures and related anisotropy effects which occur in certain industrial processes are presented for as-cast, deformed and annealed (recrystallized) Aluminium alloys and products. They are analyzed in detail and discussed based on their formation mechanisms, which are growth selection during solidification and the formation of new grains during casting and recrystallization, glide on selected slip planes during plastic deformation and oriented nucleation and oriented growth of new grains during recrystallization. Alloy composition and constitution that control microstructure evolution during processing (e.g. casting, extrusion, hot and cold rolling, annealing) determine the material quality and product performance.In these cases industrial processing of Aluminium alloys is specifically designed to control textures to achieve superior anisotropic properties and so better meet special product requirements. Examples are given for resulting properties, like strength and formability / anisotropy effects in packaging and automotive sheet applications. Other examples are given for the etching behaviour of high purity Aluminium capacitor foil and strength anisotropy of age hardened extrusions for aerospace applications.
Microstructural and Crystallographic Aspects of Yield Surface Evolution
Authors: Jeong Young Ung , Barlat Frédéric , Lee Myoung Gyu
Published: December 2011

The microstructural and crystallographic aspects, reflected at the macroscopic scale on yield surface and its subsequent evolution, are reappraised by application of crystal plasticity simulations. Strain hardening rule in the slip system is coupled to cope with latent hardening and Bauschinger effect. Uniaxial tension simulation on an isotropic polycrystalline aggregate leads to anisotropic strain hardening. Typical elements of phenomenological plastic anisotropy and hardening rules such as expansion, kinematic shift and distortion of the yield surface, are shown to be featured in crystal plasticity by tuning the slip system hardening rules appropriately.
New Model for Twin-Variant Selection in Hexagonal Alloys
Authors: Schuman Christophe , Bao L. , Lecomte J.S. , Philippe M.J. , Zhang Y. , Zhao X. , Zuo Liang , Raulot J.M. , Esling C.
Published: December 2011

A new selection criterion to explain the activation of the twinning variant is proposed. This criterion is based on the calculation of the deformation energy to create a primary twin. The calculation takes into account the effect of the grain size using a Hall-Petch type relation. This criterion allows to obtain a very good prediction for the variant selection. The calculations are compared with the experimental results obtained on T40 (ASTM grade 2) deformed by Channel Die compression.
Rolling Texture Transition in FCC Metals Using the Viscoplastic Φ-Model and Considering Mechanical Twinning
Authors: Wen W. , M’Guil S. , Ahzi S.
Published: December 2011

The viscoplastic Φ-model belongs to the same class of self-consistent models but it is based on a new theory without the Eshelby scheme. The Φ-model, by varying the parameter Φ, can predict a very large range of the texture components: from the lower (Φ →1) to the upper (Φ→0 ) bounds results. In this work, we adapt the Φ-model to take into account the mechanical twinning. This extended Φ-model is used to predict textures in FCC metals under plane strain compression test. We show that the deformation twinning plays an important role in the formation of brass-type texture.
Tracking the In-Grain Orientation Spreads in Hot-Deformed Polycrystalline Aluminium: Experiment and Finite Element Simulation
Authors: Quey R. , Driver Julian H. , Dawson Paul R.
Published: December 2011

The development of orientation spreads within individual grains of a polycrystal submitted to large deformations is analysed by both experiment and simulation. In the experiment, 176 grains on an internal surface of a split sample were followed by detailed EBSD measurements, at successive strains up to 1.2. In parallel, a high-resolution finite element simulation has been carried out on the same polycrystal configuration. For both experiment and simulation, hundreds to thousands of orientation values were obtained in each grain. Most grains showed a “unimodal” rotation, composed of an average rotation and an orientation spread. The experimental and simulated orientation spreads were compared through different statistical metrics. The average lattice disorientations are found to increase rapidly at the beginning of the deformation and to saturate at high strains. The orientation spreads are also analysed in terms of anisotropy along the sample axes. It is shown that the orientation spreads are aligned preferably along TD at the beginning of the deformation, then tend to move to RD in the experiment, and RD or ND in the simulation.
The Effect of through-Thickness Texture Inhomogeneity on Roping Behavior in AA6111 Al-Si-Mg Alloy
Authors: Jin Hai Ou , Gupta A.K.
Published: December 2011

The through-thickness textures of different variants of AA6111 T4 sheets were investigated by using X-ray pole figure technique, scanning electron microscopy (SEM), and electron back scattering diffraction (EBSD) technique in SEM. The roping behaviors of the sheets were determined and corelated to the through-thickness texture inhomogeneity. It has been demonstrated that (i) roping is due to through-thickness texture inhomogeneity, (ii) roping occurs in AA6111 when the cube and Goss texture components segregate along the rolling direction (RD) and alternate in the transverse direction (TD), (iii) the texture alignment from sheet surface to 1/5 thickness is most critical to roping behavior, while the effect of texture in the sheet centre is masked by the surface layer, and (iv) the texture alignment can be attributed to the stability of cube and Goss in rolling, and the nucleation and grain growth advantage of cube and Goss during heat treatments.
Precipitation and Texture Formation in Interstitial Free High Strength (IFHS) Steels: A Short Review
Authors: Ray Ranjit Kumar , Ghosh P.
Published: December 2011

Interstitial free high strength steels (IFHS) are widely used in the automobile sector due to their high strength and excellent formability. However, these properties of IFHS steels are very much dependent on the processing parameters, like hot rolling, cold rolling and annealing. The composition and processing parameters influence the chemistry and morphology of the precipitates formed in these steels, which in turn control the texture and thus the deep-drawability. This review will briefly summarize the findings of the ongoing research in this area. An attempt will also be made to elucidate the correlation of precipitation behavior and texture formation (and thus formability) in these steels.
Formation Process of Texture in AZ80 Alloy during High Temperature Plane Strain Compression Deformation
Authors: Kim Jinuk , Okayasu Kazuto , Fukutomi Hiroshi
Published: December 2011

Formation process of textures in AZ80 is investigated on polycrystal specimens with different initial textures by plane strain compression deformation at 673 K and 723 K with strain rates between 5.0×10-4s-1 and 5.0×10-2s-1. Three kinds of specimens were taken out from the extruded bars with (direction of the extrusion) fiber texture by changing the geometrical relationship with the extrusion direction. In the case of the specimen having parallel to the compression direction before deformation, the initial fiber texture gradually transformed into several orientations with increasing strain at 723K with a strain rate of 5.0×10-2s-1. oriented grains, which was not seen in the pole figures before deformation appeared after the deformation up to -1.0 in true strain. The other two kinds of specimens have compression directions perpendicular to direction. The textures after deformation of these two kinds of specimens also consisted of several components. Some of them are common among the three kinds of specimens and the others are retained components of the initial texture.
Texture Analysis for Determining the Rate Controlling Process in the Transient and Steady State Regions of Superplastic Flow
Authors: Padmanabhan K. Anantha , Sankaran S. , Sarma V. Subramanya , Suwas Satyam , Engler Olaf , Miller-Jupp Simon
Published: December 2011

Even anisotropic superplastic flow, which is a result of an elongated grain shape and texture, can lead to extreme elongations to fracture (superplasticity). Therefore, to identify the mechanisms of deformation present during superplastic flow alone, the effects of the microstructure should be eliminated first. Using an Al 5083 alloy, in which an equi-axed microstructure is present from the beginning, it is shown that grain boundary sliding, accompanied by grain rotations, is the rate controlling mechanism.
Observations on the Effect of a High Magnetic Field Annealing on the Recrystallized Microstructure and Texture Evolution in Pure Copper
Authors: Tong He , Kang Tian You , Wang Zhi Jia , Zhao Xiang , Zuo Liang
Published: December 2011

The cold-rolled pure copper sheets were annealed without and with a high magnetic field of 12T. The results showed that the application of the magnetic field could promote the recovery and recrystallization processes of cold rolled pure copper. The intensity of Cube component in the field treated samples was obviously higher than that in the non-field treated ones at the same annealing temperature.
Recrystallization Kinetics and Texture Evolution during Annealing of Fe-23.2Mn-0.57C Alloy
Authors: Lu Ya Ping , Molodov Dmitri A. , Gottstein Günter
Published: December 2011

The recrystallization behavior of a 50% cold rolled Fe-23.2Mn-0.57C alloy was investigated during annealing at temperatures between 560°C and 670°C. The recrystallization kinetics were characterized by microhardness tests. X-ray diffractions and EBSD measurements were used to characterize the grain microstructure and texture evolution during annealing. The obtained experimental data were evaluated in terms of the JMAK model. The annealing texture in the investigated temperature range was very weak.
Texture Evolution in Thermomechanically Control Processed Multiphase Medium Carbon Microalloyed Steel: Forged, Rolled and Low Cycle Fatigued Microstructures
Authors: Sankaran S. , Suwas Satyam
Published: December 2011

A ferrite-bainite-martensite (F-B-M) microstructure was produced in a medium carbon microalloyed steel through two routes, namely, low temperature finish forging or rolling, followed by a two step cooling and annealing. The texture formed in control forged and rolled material after two step cooling followed by annealing (TSCA) was examined. Texture investigation was also carried out after low cycle fatigue testing at low and high total strain amplitudes. Transmission electron microscopy was employed to study the microstructural evolution. Fatigue tested F-B-M microstructure obtained through the rolling route was stable up to a total strain amplitude of 0.6%. This paper reports the evolution of texture and microstructure in two-step cooled F-B-M microstructure and their stability during fatigue loading.
Advanced Methods and Tools for Reconstruction and Analysis of Grain Boundaries from 3D-EBSD Data Sets
Authors: Konijnenberg P.J. , Zaefferer S. , Lee S. B. , Rollett A.D. , Rohrer G.S. , Raabe D.
Published: December 2011

We report the recent development of a 3D orientation data post-processing software, which we refer to as QUBE. Amongst other functionalities, it offers the possibility to specify the spatial and orientational distribution of boundary normals. We describe a method to reconstruct a voxel-accurate and smooth 3D boundary triangle mesh by algorithmic means. A proof of concept is given by a benchmark on a generic dataset and we demonstrate a first result with the description of selected grain boundaries in an Fe-28%Ni sample.
In-Situ Texture Measurements by Synchrotron Radiation of TRIP Steel during an Austempering Treatment
Authors: Petrov Roumen H. , León-García Orlando , Sharma Hemant , Lee Kyoo Young , Offerman S. Erik , Kestens Leo A.I.
Published: December 2011

Texture formation during an austempering treatment of a TRIP-assisted steel was studied by in-situ texture measurements with a high energy source (synchrotron). Samples from a cold rolled sheet were subjected to a complete heat treatment cycle for TRIP steels including reheating to the intercritical (α+γ) temperature region, isothermal soaking and bainitic holding (austempering) at 400°C for 600s. At specific points of the thermal cycle {200}γ, {220}γ {222}γ, {331}γ and {200}α, {211}α and {220}α Debye rings were recorded and the corresponding incomplete pole figures were calculated. The latter were used to derive the orientation distribution functions (ODFs) of BCC and FCC phases at specific steps of the annealing process after assuming the orthotropic sample symmetry. The acquired data for the texture evolution during the α–γ–α phase transformation showed that during the reheating for intercritical annealing the gamma phase with {011} orientation is among the first to nucleate from the recrystallized α phase during heating and the Goss and Cube orientations are among the principal gamma phase components which transform to BCC phase after cooling.
Generalized Pole Figures and Stored Energy Distribution Function Obtained by X-Ray Diffraction
Authors: Cruz-Gandarilla Francisco , Salcedo-Garrido A.M. , Baudin Thierry , Mendoza-León H. , Penelle Richard
Published: December 2011

Abstract. Anisotropy of physical and mechanical properties of textured polycrystalline materials strongly depends on microstructural characteristics, such as subgrain sizes, lattice deformations, etc. Generalized Pole Figures (GPF) are an attempt to estimate the anisotropy of these properties; so, the energy stored during plastic deformation is a key parameter in primary recrystallization. In this work, the technique to measure GPF (measurements and software) was implemented for X-Ray diffraction and applied to study of property anisotropy of a Fe50%Ni alloy. GPF’s of texture, crystallite size, stored energy and diffraction peak shift, (among others) have been characterized. The Full Width at Half Maximum (FWHM) of obtained instrumental functions shows that defocusing is significant for polar angle higher than 50°. The mixing parameter of the pseudo-Voigt function using in fitting, presents important dispersions.
Deformation Temperature Effects on Microstructure and Texture Evolution in High Strain Rate Extrusion-Machining of Mg-AZ31B
Authors: Sagapuram Dinakar , Efe Mert , Moscoso Wilfredo , Chandrasekar Srinivasan , Trumble Kevin P.
Published: December 2011

Deformation microstructure and texture in Mg-AZ31B bulk strips processed through extrusion-machining were studied as a function of deformation temperature. At warm deformation temperatures (~200°C), cold-worked type microstructures with predominant tilted basal texture were observed. With increase in temperature, grain structure sharply transformed into equiaxed type with predominant in-plane basal texture. This sharp transition was found to be consistent with change in temperature dependent dynamic recrystallization mechanism from continuous to discontinuous type.
Local Strain Calculations Using Electron Backscattered Diffraction (EBSD) Measurements and Digital Image Processing
Authors: Mukherjee S. , Mishra Sushil K. , Samajdar Indradev , Pant Prita
Published: December 2011

Measurement of local strains in poly-crystalline materials, subjected to relatively large plastic deformation, is a challenging problem. In this paper we report a novel approach for the calculation of local strains at microscopic levels using Electron Backscattered Diffraction measurements, and subsequent use of digital image processing and a simple algorithm. Identical grains, of a fully recrystallized commercial AA1050 sheet, were indexed before and after a tensile strain of 0.262. Normal and shear strains were calculated by estimating the changes in grain shape and in plane rotation. An excellent correlation was obtained between measured in-grain misorientation developments and the estimated in-grain von-Mises equivalent strains.
Abnormal Growth Mechanisms of Goss Grains in Grain-Oriented Electrical Steels
Authors: Mao Wei Min , Li Y. , Yang Ping , Guo Wei
Published: December 2011

The possible mechanisms concerning abnormal growth of Goss grains in grain oriented electrical steels were investigated. The density of inhibitor particles near sheet surface, where the Goss grains located, was lower than that in center layer before secondary recrystallization, and the grains near surface could grow more easily because of reduced pinning effect. Few Goss grains could survive the growth competition and reach the sheet surface, after which the inhibitor particles inside the Goss grains coarsened slower. The phenomenon resulted in easy growth of the Goss grains at the expense of smaller neighboring grains while they could hardly be consumed by larger neighboring grains during the high temperature secondary recrystallization. Very large final size of the Goss grains was then obtained. The mechanisms were discussed based on the hot rolling characteristics and the elastic anisotropy of the ferrite matrix.
Cellular Automata Simulation of Textural Evolution during Primary Static Recrystallization of IF Steel
Authors: Kim Dong Kyu , Jung K.H. , Lee H.W. , Im Yong Taek
Published: December 2011

A two dimensional probabilistic cellular automata model is used to simulate primary static recrystallization of interstitial free (IF) steel. The present study is to investigate the effect of curvature-driven pressure that is induced by protrusions/retrusions of recrystallization fronts on the microstructural and textural evolution during recrystallization. It was found that local interface migration of protrusions/retrusions of recrystallization fronts could significantly affect the kinetics, grain morphology and annealing texture according to the present investigation.
Influence of Nb-Ti Composition on Recrystallization of Ferritic Stainless Steel
Authors: Yang Yi Qiao , Liu Yan Dong
Published: December 2011

An experimental study of the microstructural and texture evolution attending recrystallization of Nb-Ti stabilized ferritic stainless steel is presented. Two specimens with different Nb-Ti compositions, TCS345 and B4003, have been selected for comparison. The result shows that, after annealing at 750 °C for 5min, the major orientation in the TCS345 specimen locates at {111}, microstructures presents an equiaxed grain morphology, whereas the texture in the B4003 is not typical recrystallization texture and remains weak, indicating recrystallization occur preferentially to the TCS345 sheet. And after continuous annealing at 850°C for 5 min, the texture in TCS345 remains stronger than in the B4003, indicating that the additional amount of Nb-Ti acts to significantly hinder the recrystallization process.
Texture Evolution during Recrystallisation of Cold Rolled TWIP Steel
Authors: Saleh Ahmed A. , Pereloma Elena V. , Gazder Azdiar
Published: December 2011

A TWinning Induced Plasticity (TWIP) steel was cold rolled to 42% thickness reduction followed by isochronal annealing for 300 s between 600-850 °C. Bulk texture evolution during recrystallisation was investigated by X-Ray Diffraction. While the development of the α-fibre after cold rolling is typical of low stacking fault energy materials, anomalously higher intensities were noted for the Goss ({110}) compared to Brass ({110}) orientations. Upon recrystallisation, the main rolling texture components were retained and ascribed to nucleation at orientations close to those of the deformed matrix followed by annealing twinning which leads to crystallographically identical variants. Unlike previous texture investigations on austenitic steels, the relatively homogeneous deformation microstructure and uniform distribution of subsequent nucleation sites led to the retention of the F ({111}) orientation. Moreover, the firsthand observation of the Rotated Copper ({112}) orientation in TWIP steel is attributed to the second order twinning of the A ({110}) orientation.
Study of Micro-Texture during Recovery and Recrystallisation in Folded BCC and FCC Sheet Samples
Authors: Ubhi Harvinder Singh , Jiang Hui
Published: December 2011

The sheet folding process generates both tensile and compressive strains across the folded section, producing systematic strain and texture gradients. In this investigation the EBSD technique has been used to gain insight into this phenomenon in folded ferritic steel and nickel alloys, both in the as folded and after annealing conditions. As expected in the fcc material the {111} and {110} fibre texture components get reinforced in the tensile and compressive regions respectively, while the {110} and {111} components are reinforced in the bcc material during folding. After annealing at 600oC for 40 minutes the texture components formed during the folding process are retained despite the formation of new strain free grains. The new grains were found to be slightly larger in the tensile regions than in the compressed regions this was the case for both materials. However, in the mid-region of the section in the nickel alloy abnormal grain growth took place, while only recovery was observed in the ferritic alloy.
Electrochemical Characterization of Low Temperature Thermal Aging Embrittlement of Stainless Steel 304L Weld
Authors: Chandra Kamalesh , Kain Vivekanand , Raja V.S. , Tewari R. , Dey G.K.
Published: December 2011

Thermal aging embrittlement of type 304L stainless steel weld is investigated on the basis of changes in microstructure, microhardness and electrochemical behavior after aging up to 20,000 h at 335, 365 and 400 °C. Spinodal decomposition and G-phase precipitation in the ferrite was observed after thermal aging. Aging led to increase in the hardness of ferrite phase while there was no change in the hardness of austenite. The changes in electrochemical behavior due to aging were studied using double loop electrochemical potentiokinetic reactivation (DL-EPR) test. Aging led to increase in the DL-EPR value which is attributed to Cr depletion in the ferrite phase.
Statistical Analysis of Grain Boundaries in the Space of Macroscopic Boundary Parameters
Authors: Morawiec Adam
Published: December 2011

Current issues concerning the characterization of grain boundary networks via five-dimensional (5D) grain boundary distributions are considered. A quantitative measure of reliability of such distributions is adapted from conventional texture analysis. Application of the measure shows that with the currently available size of experimental data sets of boundary parameters, only strong components of the boundary distributions can be reliably evaluated. Improvements of the computational part of the analysis are possible if the the binning based on Euler and polar/azimuth angles is replaced by searching the data sets based on a suitably defined distance. Moreover, it is indicated that for textured materials the stereological approach has limited reliability. Finally, it is suggested that coherent twins can be used for estimating experimental errors, and that the distributions cannot be a basis for conclusions about tilt boundaries unless additional restrictions are applied. The approach used in the paper is theoretical with support by computer simulations.
Origin and Role of Σ3 Boundaries during Thermo-Mechanical Processing of a Ti-Modified Austenitic Stainless Steel
Authors: Mandal Sumantra , Bhaduri A.K. , Sarma V. Subramanya
Published: December 2011

The origin and role of S3 boundaries during dynamic recrystallization (DRX) and grain boundary engineering (GBE) of a Ti-modified austenitic stainless steel (alloy D9) is studied. Hot deformation tests were carried out on solution-annealed (SA) specimens to study the DRX behavior whereas a series of cold deformation and annealing were performed on SA specimens to realize GBE microstructure. A linear relationship between the area fraction of DRX and the number fraction of Σ3 boundaries was observed during hot deformation. This high fraction of Σ3 boundaries could account for the formation of coherent annealing twins by “growth accidents” during DRX. For certain combinations of cold deformation and annealing, a significant increase in S3 boundaries was observed. In contrast to hot deformation, majority of these new S3 boundaries during cold deformation and annealing were formed by geometrical interactions between the pre-existing Σ3 boundaries. The role of the S3 boundaries during DRX and on tailoring microstructure through grain boundary engineering approach is discussed.
Effect of Uni-Axial Tensile Deformation on Microstructure and Magnetic Properties of 3.2% Si Grain Oriented Electrical Steel
Authors: Shekhawat Satish Kumar , Basavaraj V. , Samajdar Indradev , Suresh K.G. , Pant Prita , Hiwarkar V.D. , Dumbre Jayshri , Ingle A. , Chakerbarti S. , Mani K.V.
Published: December 2011

Cold rolled grain oriented (CRGO) steel was deformed by uni-axial tensile loading in three different directions: Rolling Direction (RD) (110) , Transverse Direction (TD) (110) and 45° to RD (110) . Deformation behavior was found to be different for the different directions of loading. Such differences were biased by the heat flattening coating and could be captured, effectively, through discrete dislocation dynamics simulations. Results from texture and micro-texture studies, mechanical tests and magnetic measurements show a clear relationship between strain hardening exponent (n) and degradation in magnetic properties (watt loss and permeability). These were also related to misorientation developments, relative recovery and deviations from ideal Goss orientation.
Orientation Evolutions During Hot Rolling of Electrical Steel Containing Initial Columnar Grains
Authors: Yang Ping , Shao Y.Y. , Mao W.M. , Jiang Q.W. , Jin W.X.
Published: December 2011

The texture evolution in the surface and center layer of hot rolled electrical steel containing initial columnar grains with their <100> nearly along ND, RD and TD of sheets were determined by EBSD technique. The transition from Goss to Brass or Copper orientation in surface was analyzed. The difference in texture of center layers in these samples was compared. In particular, orientation evolutions within grains and at grain boundaries of different types of orientations were explored. The results are discussed in terms of the special alignments of grain boundaries among columnar grains.
Texture Evolution during Asymmetrical Warm Rolling and Subsequent Annealing of Electrical Steel
Authors: Nguyen Minh Tuan , Sidor Jurij J. , Petrov Roumen H. , Kestens Leo A.I.
Published: December 2011

The core loss and magnetic induction of electrical steels are dependent on the microstructure and texture of the material, which are produced by the thermo-mechanical processing. After a conventional rolling process, crystal orientations of the α-(//RD) and γ-(//ND) fibers are strongly present in the final texture. These fibers have a drastically negative effect on the magnetic properties of electrical steels. By applying asymmetric rolling, significant shear strains could be introduced across the thickness of the sheet and thus a deformation texture with more magnetically favorable components is expected. In this study, an electrical steel of 1.23 wt.% Si was subjected to asymmetric warm rolling in a rolling mill with different roll diameters. The evolutions of both deformed and annealed textures were investigated. The texture evolution during asymmetric warm rolling was analyzed by crystal plasticity simulations using the ALAMEL model. A good fit between measured and calculated textures was obtained. The annealing texture could be understood in terms of an oriented nucleation model that selects crystal orientations with a lower than average stored energy of plastic deformation.
Annealing Behaviour of Ferritic HT-9 Steel
Authors: Sahoo Santosh Kumar , Gaffney V.N. , Chatterjee A. , Murty Korukonda L.
Published: December 2011

Annealing behaviour of ferritic HT-9 stainless steel plates was investigated through evolution of microstructural, textural and mechanical properties. Microstructural observations showed two important findings: (a) abnormal grain growth occurs at higher annealing temperatures, (b) drop in in-grain misorientation with increasing annealing temperature. However, textural results showed an increase in texturing till 500oC annealing and a clear drop in texturing beyond 500oC annealing. The strength (both yield and tensile) decreased with increase in testing temperature and the micro-hardness values decreased with increase in annealing temperature. Dynamic strain ageing was observed at certain strain rates and testing temperatures. The onset of the serrated yielding at low temperature limit estimated from the strain rate-temperature plot was found out to be ~ 94kJ/mol identifiable with that for migration of C and N.
Deformation Induced Phase Seperation of Ni45Co5 Mn36.7In13.3 Alloy at High Temperature
Authors: Wang Gang , Wang Chun Yan , Chen Zhe , Zhao Wen Ru , Liu Yan Dong , Wang Yan Dong , Zuo Liang
Published: December 2011

NiMnCoIn alloys are new-type magnetic shape memory alloys (MSMAs) in which a reversible magnetic-field-induced phase transformation was observed. They are ideal candidates of materials used in actuators and sensors. The polycrystalline NiMnCoIn alloys are generally brittle so that they can not be easily deformed into the shape applicable to actuators and sensors until now. In the present paper, the influence of hot deformation on the microstructure of Ni45Co5 Mn36.7In13.3 alloy was studied. The experimental results showed that second phase was observed after deformation at high temperature between 800~900 °C and at strain rate lower than 4×10-3s-1. The content of Co of second phase was higher than the matrix alloy, while the content of In was lower than the matrix alloy. It was determined by TEM measurements as γ phase with fcc structure which was popular in NiFeGa and NiMnGaCo alloys. It is possible to improve the ductility of Ni45Co5Mn36.7In13.3 alloy by control of amount and distribution of γ phase by hot deformation.
Evolution of Microstructure and Crystallographic Texture in AA2014 Aluminium Alloy during Equal Channel Angular Extrusion
Authors: Giribaskar Sivaswamy , Suresh K.S. , Gouthama  , Suwas Satyam
Published: December 2011

Present work addresses the evolution of texture and microstructure of equal channel angular extrusion (ECAE) processed AA 2014 Al alloy upto four passes at room temperature by adopting route BC. TEM is used to assess the microstructural changes during each ECAE pass. Texture measurements on samples of each pass were carried out by XRD technique. The evolution of texture components after each ECAE pass are analyzed and the changes are discussed with respect to the initial texture.
Effect of the Rotating Speed of Centrifugal Machine on Microstructures and Properties of Recycled WCP/Fe-C Composites
Authors: Song Yan Pei , Li Yong Kai , Wang Hui Gai
Published: December 2011

The dead or scrap WCP/Fe-C composites parts were remelted via medium frequency induction furnace. Two recycled composites rings were made of the remelted mixture by centrifugal casting method at 720rpm and 920rpm, respectively. The effect of rotating speed of centrifugal machine on microstructures and properties of the recycled composites rings were investigated by mechanical property tester, SEM, EDS, and XRD. The results show that the recycled rings are a composite structure consisting of outer recycled composites region reinforced with undissoved WCP and core Fe-C alloy region unreinforced. The undissoved WCP-distribution in the recycled composites region is even. At the rotating speed of 720 rpm, the particle volume fraction in the recycled composites region reaches 54 vol.%, the hardness and impact toughness attain to HRC55.8 and 3.5J/cm2, respectively. As the rotating speed is raised to 920 rpm, the particle volume fraction rises to about 70 vol.%, the hardness increases to HRC63.3 and yet the impact reduces to 2.8 J/cm2. The microstructure in the inner Fe-C alloy region consists of bainitic, precipitated carbides with short rod like shape and graphite phase. Finally, the high-speed sliding wear behaviour of the recycled composites rings was investigated in the paper. Keywords: The dead or scrap composites parts; Recycled composites; rotating speed of centrifugal machine; Microstructures and properties.
The Resistance of SiC/Al Layered Composite to Ballistic Impacting
Authors: Huang Dan , Zhao Wu
Published: December 2011

Ballistic impacting test has been conducted on laminated SiC/Al-Cu composite with three layers ceramic plates and metal multi-constrain, while the target sample was prepared through squeeze casting. The ballistic testing result showed that composite exhibited good structural integrity. Mass loss and length loss of projectile are 63.65% and 65.43% respectively, mainly resulted from abrasion of crushed ceramic particles and melting erosion itself. Multi-constrain of metal ensured to maximize the role of abrasion of crushed ceramic powder, in addition, the heat generated at instantaneous projectile-target contact led to partial corrosion on projectile. Subject to ballistic impacting, SiC ceramic was transgranularly fractured and crushed, metal lining was melt, deformed and destroyed, as well as the interface dissociation happened between ceramic and metal. These processes absorbed great kinetic energy of projectile, so as to stop the penetration of incident mass within the laminated structure. Layered composite failure was completed under synergistic effect of three fracture modes, including ceramic brittle fracture, interface debonding and metal fracture.
Numerical Simulation and Experiment Research on Thick Plate Multi-Point Forming Process with Elastic Cushion
Authors: Wang Li Yong , Li Le
Published: December 2011

Multi-point forming (MPF) is an advanced flexible manufacturing technology for three-dimensional sheet metal forming. The substance of MPF is replacing the conventional solid dies by a set of discrete punches called ‘‘punch group’’. Because the reconfigurable discrete punches are used, part manufacturing costs are reduced and manufacturing time is shortened. However due to the discrete contacts between the workpiece and punches, the dimple defects occurred, which are inevitable and particular for MPF. For thick plate, the surface defect is the mainly dimple defect during its MPF process. In this study, elastic cushion was proposed to prevent these surface defects. The dynamic explicit finite element method was chosen to implement the simulation of MPF process. The Hill’s anisotropic yield criterion was used to describe the workpiece material behavior, and the elastic cushion was described with using the hyperelastic material model. The method to determine each punch position to construct forming surface was introduced. The MPF process with and without using elastic cushion was simulated to study the effect of the elastic cushion on preventing the surface defects. The relevant experiment was implemented, and it verified that the elastic cushion is effective method to suppress the surface defects during the thick plate MPF process. Keyword: flexible forming process (FFP), elastic cushion, surface defects, multi-point forming (MPF), thick plate, numerical simulation
Influence of Steel Slag on Compressive Strength and Durability of Concrete
Authors: Zhu Jian Ping , Guo Qi Lei , Gao Xiang , Li Dong Xu
Published: December 2011

The present research study investigates the compressive and durable properties of concretes with steel slag, a by-product of the conversion process of iron to steel. For this purpose, a reference sample and twenty-four concretes containing steel slag were tested. The steel slag fraction used was “5–20 mm”, and the surface area of steel slag powder was 450m2/kg. Compressive strength at 7 and 28 days, and chloride penetration properties were measured. It is concluded that steel slag can be used in the production of concrete. In addition, the steel slag concretes present satisfactory physical properties. When proper amount of steel slag powder and steel slag fraction were used the concrete properties can be better than the blank one. Keywords: Steel slag, cement, coarse aggregate, concrete, durability
Derivation and Application for Calculation of Carbon Content in Austenitizing of Cast Iron
Authors: Gong Wen Bang , Luo Li , Chen Guo Dong , Xiang Gang Yu
Published: December 2011

In this paper, a formula for the calculation of carbon content during austenitizing of cast iron was deduced, considering the effect of silicon content. According to this formula, carbon content of austenite at a certain austenization temperature for a cast iron with given composition can be easily calculated, and the austenization temperature for getting the expected carbon content in the austenite can also be determined. Besides, according to the relationship between austenization temperature Tx and the according carbon content Cax, and considering the effect of silicon content, the carbon content of the austenite in the commonly used cast iron during heat treatment was calculated. The formula can be as a theoretical basis for determined austenization temperature and carbon content in austenite during heat treatment of cast iron, in particular, can play an important role in heat treatment of austempered ductile iron. Keywords: cast iron heat treatment; diffusion of carbon; carbon content in austenite
Simulation of the Young’s Modulus Anisotropy in CVD Diamond Film
Authors: Zhu H.X. , Gu C. , Xue Y.D. , Ren Feng Zhang
Published: December 2011

The relationship between textures and Young’s modulus in CVD diamond films was simulated based on the phenomenological theory, which indicates the textures induce the Young’s modulus anisotropy. The increase of methane concentration changes the density of different fiber textures in diamond films, which induces the increase of Young’s modulus in the directions that parallel to the film surface. Among the textures, {111} texture is of no influence whereas {011} texture has the maximum influence on the Young’s modulus anisotropy of diamond film.
Effect of Bell-Type Annealing Process on Properties of SPCC Cold-Rolled Steel Sheet
Authors: Wang Zhi Hua , Zhao Yan Ping , Li Yun Tao , Wang Jun , Zhang Jian
Published: December 2011

This study simulated Bell-type annealing technology under laboratory conditions, and researched the effect of annealing time on the mechanical properties of SPCC cold-rolled steel sheet. The results indicate that the yield strength decreased with the extending of time; the plastic strain increases with the elongation of annealing time till a given time, and then decreased with the time extending; the cold-rolled specimen brittle fractured in tension while the annealed specimen shear fractured. Key words: microstructure mechanical properties Bell-type annealing SPCC cold-rolled steel sheet
A Numerical Simulation of Microstructure Evolution of GH4169 Alloy Blade during Finish Forging
Authors: Qi G. X. , Mei Rui Bin , Wang F , Bao L
Published: December 2011

In order to predict the microstructure evolution and grain size of GH4169 alloy blade in finish forging process and optimize the parameters, a coupled simulation between thermal mechanical and microstructure evolution was realized through embedding the developed user subroutines into the DEFORM-3D software. The temperature, equivalent strain, dynamic recrystallization fraction, average grain size and grain size distribution were predicted and discussed. The experimental results of microstructure under the same forging condition were investigated. The average grain degree in the blade rabbet and body are 8 and 10 respectively. The calculated results of microstructure have a good agreement with the measured value from experimental data and the prediction error of average grain size is less than 6.7%. The developed program is reliable and the accuracy is satisfying. The distribution of grain size along the blade body is decreased from the middle to the leading and back edge. The shape and microstructure after finish forging under the condition of technology parameters meet the user’s requirement. Keywords: Blade, GH4169 alloy, Numerical simulation, Microstructure, Forging
Modeling of Carburization and Thermal Stress Analysis for Ethylene Cracking Furnace Tube
Authors: Geng Lu Yang , Gong Jian Ming , Qin Xiao Yan , Shen Li Min
Published: December 2011

The ethylene cracking furnace tube is one of the most important components of an ethylene cracking furnace. Carburization of furnace tube is one of the most important causes which lead the tube to fail. In this paper, the model that describes diffusion of carbon and the precipitation of carbides was established based on Fick’ law and equilibrium constant method. The finite difference method was adopted to simulate the distribution of carbon concentration. By applying the model, the distribution of carbon concentration along thickness in HP-Nb tubes was predicted for the different service times. According to the temperature distribution of furnace tube, obtained by the analysis of heat transfer, the thermal stresses of the furnace tube with various carburization extents were analyzed by using the finite element code ABAQUS for the actual heating process of an ethylene cracking furnace. The analysis results show that the maximum circumferential thermal stress exists near the inner wall of the carburized tube, which usually causes cracking of the carburized tube along the longitudinal direction.