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Occurrence Of Surface Defects On Strips During Hot Rolling Process By Fem, Hai-Liang Yu, Kiet Tieu, Cheng Lu, Guan-Yu Deng, Xiang-Hua Liu Jan 2013

Occurrence Of Surface Defects On Strips During Hot Rolling Process By Fem, Hai-Liang Yu, Kiet Tieu, Cheng Lu, Guan-Yu Deng, Xiang-Hua Liu

Faculty of Engineering and Information Sciences - Papers: Part A

During a hot rolling process, surface defects on strips can severely affect the quality of the rolled product, particularly for two conditions: (1) there are initial defects on continuous casting slabs that propagate and/or are inherited from those on the surface of rolled steels from upstream rolling processes; and (2) there are no initial defects on continuous casting slabs, and they consequently appear on the surface of rolled steels due to improper rolling technologies. In this paper, the authors present a new 3D finite element model coupled with constrained node failure to understand better the initiation and growth of surface …


Modeling Of Thin Strip Profile During Cold Rolling On Roll Crossing And Shifting Mill, A Aljabri, Z Y. Jiang, D B. Wei, X D. Wang, H Tibar Jan 2013

Modeling Of Thin Strip Profile During Cold Rolling On Roll Crossing And Shifting Mill, A Aljabri, Z Y. Jiang, D B. Wei, X D. Wang, H Tibar

Faculty of Engineering and Information Sciences - Papers: Part A

Strip profile control in cold rolling of thin strip is a difficult and challenge problem found in industry. Currently using the novel type of strip rolling mill, such as the work roll crossing and shifting is the one of the main methods to control the strip profile quality in cold rolling. In this paper, 3-D finite element simulation models of the thin strip profile in cold rolling for the work roll crossing and shifting system were successfully developed. The strip profile and edge drop are discussed considering both crossing angle and shifting value of the work rolls. The research shows …


Characterisation Of Metal Deposition During Additive Manufacturing Of Ti-6al-4v By Arc-Wire Methods, Nicholas Hoye, E C. Appel, Dominic Cuiuri, Hejie Li Jan 2013

Characterisation Of Metal Deposition During Additive Manufacturing Of Ti-6al-4v By Arc-Wire Methods, Nicholas Hoye, E C. Appel, Dominic Cuiuri, Hejie Li

Faculty of Engineering and Information Sciences - Papers: Part A

This study considers the use of the gas tungsten arc (GTA) welding process in conjunction with 'cold' wire addition to give layer-wise build-up of thin walled structures, simulating those commonly found in aerospace applications, which may in the future be manufactured by additive means. Taguchi DOE and multiple regression analysis methods have been applied to quantitatively establish relationships between common process parameters including arc length, arc current, travel speed and wire feed speed and resulting weld bead geometries and actual metal deposition rates. Mathematical expressions for build-up height, thickness and surface roughness are presented and evaluated against experimental data, with …


Multi-Factor Coupling System Characteristic Of The Dynamic Roll Gap In The High-Speed Rolling Mill During The Unsteady Lubrication Process, Qiaoyi Wang, Zhengyi Jiang, Jingwei Zhao, Min Fang Jan 2013

Multi-Factor Coupling System Characteristic Of The Dynamic Roll Gap In The High-Speed Rolling Mill During The Unsteady Lubrication Process, Qiaoyi Wang, Zhengyi Jiang, Jingwei Zhao, Min Fang

Faculty of Engineering and Information Sciences - Papers: Part A

In the present work, a multi-factor coupling dynamic model of a rolling mill system for a dynamic roll gap during an unsteady lubrication process was developed on the basis of the rolling theory, lubrication and the friction theory, and the mechanical vibration theory. The multi-factor coupling model of interfacial film binding was coupled with the rolling force model, dynamic roll gap interface friction model and work roll movement model. The corresponding distributions of friction and pressure at varying surface roughness and times were systematically analyzed during the unsteady mixed lubrication process. The effects of the main processing parameters on the …


Microstructure And Texture Evolution In A Twinning-Induced-Plasticity Steel During Uniaxial Tension, Ahmed A. Saleh, Elena V. Pereloma, Azdiar A. Gazder Jan 2013

Microstructure And Texture Evolution In A Twinning-Induced-Plasticity Steel During Uniaxial Tension, Ahmed A. Saleh, Elena V. Pereloma, Azdiar A. Gazder

Faculty of Engineering and Information Sciences - Papers: Part A

A combination of electron back-scattering diffraction and X-ray diffraction was used to track the evolution of the microstructure and texture of a fully recrystallized Fe-24 Mn-3 Al-2 Si-1 Ni-0.06 C twinning-induced-plasticity steel during interrupted uniaxial tensile testing. Texture measurements returned the characteristic double fibre texture for face-centred cubic materials, with a relatively stronger 〈1 1 1〉 and a weaker 〈1 0 0〉 partial fibre parallel to the tensile axis. The interaction with the stable 〈1 1 1〉 oriented grains results in preferential plastic flow in the unstable 〈1 1 0〉 oriented grains. Consequently, the grains oriented along the 〈1 1 …


The Fate Of Pharmaceuticals, Steroid Hormones, Phytoestrogens, Uv-Filters And Pesticides During Mbr Treatment, Kaushalya C. Wijekoon, Faisal I. Hai, Jinguo Kang, William E. Price, Wenshan Guo, Hao H. Ngo, Long D. Nghiem Jan 2013

The Fate Of Pharmaceuticals, Steroid Hormones, Phytoestrogens, Uv-Filters And Pesticides During Mbr Treatment, Kaushalya C. Wijekoon, Faisal I. Hai, Jinguo Kang, William E. Price, Wenshan Guo, Hao H. Ngo, Long D. Nghiem

Faculty of Engineering and Information Sciences - Papers: Part A

This study examined the relationship between molecular properties and the fate of trace organic contaminants (TrOCs) in the aqueous and solid phases during wastewater treatment by MBR. A set of 29 TrOCs was selected to represent pharmaceuticals, steroid hormones, phytoestrogens, UV-filters and pesticides that occur ubiquitously in municipal wastewater. Both adsorption and biodegradation/transformation were found responsible for the removal of TrOCs by MBR treatment. A connection between biodegradation and molecular structure could be observed while adsorption was the dominant removal mechanism for the hydrophobic (logD > 3.2) compounds. Highly hydrophobic (logD > 3.2) but readily biodegradable compounds did not accumulate in sludge. …


Image Guidance During Breast Radiotherapy: A Phantom Dosimetry And Radiation-Induced Second Cancer Risk Study, A Quinn, L Holloway, Peter Metcalfe Jan 2013

Image Guidance During Breast Radiotherapy: A Phantom Dosimetry And Radiation-Induced Second Cancer Risk Study, A Quinn, L Holloway, Peter Metcalfe

Faculty of Engineering and Information Sciences - Papers: Part A

Imaging procedures utilised for patient position verification during breast radiotherapy can add a considerable dose to organs surrounding the target volume on top of therapeutic scatter dose. This study investigated the dose from a breast kilovoltage cone-beam CT (kV-CBCT), a breast megavoltage fan-beam CT (MV-FBCT), and a TomoDirectTM breast treatment. Thermoluminescent dosimeters placed within a female anthropomorphic phantom were utilised to measure the dose to various organs and tissues. The contralateral breast, lungs and heart received 0.40 cGy, 0.45 cGy and 0.40 cGy from the kV-CBCT and 1.74 cGy, 1.39 cGy and 1.73 cGy from the MV-FBCT. In comparison to …


On The Evolution And Modelling Of Lattice Strains During The Cyclic Loading Of Twip Steel, Ahmed A. Saleh, Elena V. Pereloma, Bjorn Clausen, Donald W. Brown, Carlos N. Tome, Azdiar A. Gazder Jan 2013

On The Evolution And Modelling Of Lattice Strains During The Cyclic Loading Of Twip Steel, Ahmed A. Saleh, Elena V. Pereloma, Bjorn Clausen, Donald W. Brown, Carlos N. Tome, Azdiar A. Gazder

Faculty of Engineering and Information Sciences - Papers: Part A

The evolution of lattice strains in fully annealed Fe–24Mn–3Al–2Si–1Ni–0.06C twinning-induced plasticity (TWIP) steel is investigated via in situ neutron diffraction during cyclic (tension–compression) loading between strain limits of ±1%. The pronounced Bauschinger effect observed upon load reversal is accounted for by a combination of the intergranular residual stresses and the intragranular sources of back stress, such as dislocation pile-ups at the intersection of stacking faults. The recently modified elasto-plastic self-consistent (EPSC) model which empirically accounts for both intergranular and intragranular back stresses has been successfully used to simulate the macroscopic stress–strain response and the evolution of the lattice strains. The …


Transition Of Ductile And Brittle Fracture During Dwtt By Fem, Youyou Wu, Hailiang Yu, Cheng Lu, A Kiet Tieu, Ajit Godbole, Guillaume Michal Jan 2013

Transition Of Ductile And Brittle Fracture During Dwtt By Fem, Youyou Wu, Hailiang Yu, Cheng Lu, A Kiet Tieu, Ajit Godbole, Guillaume Michal

Faculty of Engineering and Information Sciences - Papers: Part A

Globally, steel pipelines are widely used to transport energy in the form of liquid petroleum and natural gas. The steel used in the manufacture of these pipelines must have high strength and toughness, and high resistance to fracture. The Drop Weight Tear Test (DWTT) is the most widely used test to assess brittle fracture characteristics in steel. The zones of ductile and brittle fracture during DWTT characterize the quality of pipeline steels. In this paper, the Gurson-Tvergaard-Needleman (GTN) fracture models are coupled in a Finite Element model. The ductile and brittle fracture zones in the samples are analyzed under different …


Is It Important To Position Foot In Subtalar Joint Neutral Position During Non-Weight-Bearing Molding For Foot Orthoses?, Winson Lee, Christina Lee, Aaron Leung, Stephen W. Hutchins Jan 2012

Is It Important To Position Foot In Subtalar Joint Neutral Position During Non-Weight-Bearing Molding For Foot Orthoses?, Winson Lee, Christina Lee, Aaron Leung, Stephen W. Hutchins

Faculty of Engineering and Information Sciences - Papers: Part A

When taking molds for foot orthoses, it is accepted practice to position the subtalar joint in its neutral position. However, foot orthoses have no contact with the talus, and this leads to a hypothesis that as long as there is correction available to appropriately align the forefoot relative to the hindfoot when taking a mold, changes in subtalar joint angles do not lead to significant alterations in the plantar surface shapes of the molds taken. This study tested this presumption with 20 subjects between 22 and 46 years old. During non-weight-bearing casting, the subtalar joints were aligned at positions of …


Distortion Behavior Of A Heavy Hydro Turbine Blade Casting During Forced Air Cooling In Normalizing Treatment Process, Hailiang Yu, Jinwu Kang, T J. Wang, J A. Ma, Y Y. Hu, Tianyou Huang, S B. Wang, Y Wu, C C. Zhang, Yan-Tao Dai, P Li Jan 2012

Distortion Behavior Of A Heavy Hydro Turbine Blade Casting During Forced Air Cooling In Normalizing Treatment Process, Hailiang Yu, Jinwu Kang, T J. Wang, J A. Ma, Y Y. Hu, Tianyou Huang, S B. Wang, Y Wu, C C. Zhang, Yan-Tao Dai, P Li

Faculty of Engineering and Information Sciences - Papers: Part A

Distortion behavior of blade castings in heat treatment process determines their geometrical accuracy, and improper control of it may result in additional repair, shape righting, or even rejection. This article presents a novel approach for discovering the distortion behavior of heavy blade castings during heat treatment process in production. Real-time measurements of distortion and temperature field of a heavy hydro turbine blade casting weighted 17 ton during forced air cooling in normalizing treatment process were carried out by using deformation measurement instruments and an infrared thermal imaging camera. The distortion processes of the typical locations of blade and the temperature …


Thermal, Microstructural And Mechanical Coupling Analysis Model For Flatness Change Prediction During Run-Out Table Cooling In Hot Strip Rolling, Xiao-Dong Wang, Fei Li, Zheng-Yi Jiang Jan 2012

Thermal, Microstructural And Mechanical Coupling Analysis Model For Flatness Change Prediction During Run-Out Table Cooling In Hot Strip Rolling, Xiao-Dong Wang, Fei Li, Zheng-Yi Jiang

Faculty of Engineering and Information Sciences - Papers: Part A

Non-uniformity of temperature distribution across strip width direction is the ultimate reason why the flatness defect occurs on the strip after cooling process although the strip is flat at the exit of finishing mill. One thermal, microstructural and mechanical coupling analysis model for predicting flatness change of steel strip during the run-out table cooling process was established using ABAQUS finite element software. K Esaka phase transformation kinetics model was employed to calculate the phase transformation, and coupled with temperature calculation using the user subroutine program HETVAL. Elasto-plasticity constitutive equations of steel material, in which conventional elastic and plastic strains, thermal …


Predicting The Fate Of Emerging Trace Organic Contaminants Of Concern During Mbr Treatment Based On Their Molecular Properties, K C. Wijekoon, L D. Nghiem, F I. Hai, J Kang, W E. Price Jan 2012

Predicting The Fate Of Emerging Trace Organic Contaminants Of Concern During Mbr Treatment Based On Their Molecular Properties, K C. Wijekoon, L D. Nghiem, F I. Hai, J Kang, W E. Price

Faculty of Engineering and Information Sciences - Papers: Part A

We demonstrate that the fate of emerging trace organic contaminants during membrane bioreactor (MBR) treatment can be qualitatively predicted by assessing their molecular properties. This work futher expands the qualitative framework for the prdiction of trace organic removal by MBR treatment reported in our recent study.


Analysis Of Thermal Stress During Of Twin-Roll Casting Of Magnesium Alloy, Yucheng Zhang, T Han, Zhengyi Jiang, Dongbin Wei Jan 2012

Analysis Of Thermal Stress During Of Twin-Roll Casting Of Magnesium Alloy, Yucheng Zhang, T Han, Zhengyi Jiang, Dongbin Wei

Faculty of Engineering and Information Sciences - Papers: Part A

The process of twin-roll casting including pouring, solidifying, rolling and cooling can be accomplished in a very short time. Consequently, some important process parameters in the twin-roll casting that are difficult to be obtained in experiment can be acquired using numerical simulation. In this paper, a numerical simulation based on a 2D finite element model of vertical twin-roll strip casting of magnesium alloy has been conducted, and the thermal stress fields are significantly discussed. The influences of key process parameters consisting of submerged nozzle depth and nozzle spray angle have been studied. The thermal cracks on the surface of the …


Acoustic Emission Monitoring Of Split Formation During Charpy Impact Testing Of High Strength Steel, Andrii Kostryzhev, R B. Punch, Claire L. Davis, Martin Strangwood Jan 2012

Acoustic Emission Monitoring Of Split Formation During Charpy Impact Testing Of High Strength Steel, Andrii Kostryzhev, R B. Punch, Claire L. Davis, Martin Strangwood

Faculty of Engineering and Information Sciences - Papers: Part A

Acoustic emission (AE) monitoring has been used to detect split formation during room temperature low blow Charpy impact testing of high strength thick strip steels. The AE signal analysis identified separate signals originating from hammer impact, plastic deformation (verified using Charpy impact testing on mild steel with no splits) and split initiation/growth. The presence of splits was confirmed by sectioning and fractography, and the splits were brittle in nature. A possible correlation between the AE signal features and fracture mode is presented.


Study On Surface Roughness And Friction During Hot Rolling Of Stainless Steel 301, Dongbin Wei, Zhengyi Jiang, Junxia Huang, Aiwen Zhang, Xu Shi, Sihai Jiao Jan 2012

Study On Surface Roughness And Friction During Hot Rolling Of Stainless Steel 301, Dongbin Wei, Zhengyi Jiang, Junxia Huang, Aiwen Zhang, Xu Shi, Sihai Jiao

Faculty of Engineering and Information Sciences - Papers: Part A

A well-defined boundary condition is important for generating an accurate model for simulating metal forming process. It is important to characterize the features of the oxide scale in hot rolling of stainless steel strip. Short time oxidation tests in humid air with water vapor content of 7.0 vol. % were carried out using Gleeble 3500 thermo-mechanical simulator. The deformation, surface morphology of oxide scale, and the friction in hot rolling were studied by conducting hot rolling tests. The results show that the surface roughness decreases with an increase of reduction. The effect of oxide scale on friction and surface roughness …


Strain-Induced Phase Transformation During Thermo-Mechanical Processing Of Titanium Alloys, A Dehghan-Manshadi, Rian J. Dippenaar Jan 2012

Strain-Induced Phase Transformation During Thermo-Mechanical Processing Of Titanium Alloys, A Dehghan-Manshadi, Rian J. Dippenaar

Faculty of Engineering and Information Sciences - Papers: Part A

Strain-induced phase transformation studies have been conducted in a Ti-6Al-2Sn-4Zr-6Mo alloy. This alloy was subjected to b sub-transus deformation upon slow cooling from the b-phase field and the effect of strain on the extent and morphology of the phase transformation during hot-deformation was determined. In addition, the transformation kinetics and the morphology of the newly formed a-phase were studied following deformation under different cooling conditions. By applying strain, the rate of the b-to-a phase transformation increased significantly during deformation as well as during slow cooling following deformation. This increase in the kinetics of the b-to-a transformation can be ascribed to …


Sensitization Behaviour Of 11-12% Cr Aisi 409 Stainless Steel During Low Heat Input Welding, Cornelis Janise Van Niekerk, Madeleine Du Toit Jan 2011

Sensitization Behaviour Of 11-12% Cr Aisi 409 Stainless Steel During Low Heat Input Welding, Cornelis Janise Van Niekerk, Madeleine Du Toit

Faculty of Engineering and Information Sciences - Papers: Part A

The study comprised of the investigation into the sensitization characteristics of AISI 409 titanium stabilized ferritic stainless steel during low heat input welding. AISI 409 is a fully ferritic stainless steel used in catalytic converters and tubing for automotive exhaust systems due to the supposition that sensitization does not occur during low heat input welding. Two plates of 2 and 4 mm were tested for sensitization during low heat input welding. The study confirmed that chromium carbide (M23C6) precipitation occurs on the grain boundaries in the heat-affected zone with consequent depletion of Cr adjacent to the …


Bauschinger Effect In Microalloyed Steels: Part Ii. Influence Of Work Softening On Strength Development During Uoe Line-Pipe Forming, Andrii Kostryzhev, Martin Strangwood, Claire L. Davis Jan 2011

Bauschinger Effect In Microalloyed Steels: Part Ii. Influence Of Work Softening On Strength Development During Uoe Line-Pipe Forming, Andrii Kostryzhev, Martin Strangwood, Claire L. Davis

Faculty of Engineering and Information Sciences - Papers: Part A

The Bauschinger effect (a reduced yield stress at the start of reverse deformation following forward prestrain) is an important factor of strength development for cold metal forming technology. In steels, the magnitude of the Bauschinger effect depends on composition, through the presence of microalloy precipitates, and prior processing, through the size and distribution of the microalloy precipitates and the presence of retained work hardening. In this article, the parameters of the Bauschinger effect and work hardening (coefficient and exponent) in forward and reverse deformations were quantitatively related to the particle number density and dislocation density for two high-strength low-alloy (HSLA) …


Study On Oxidation Of Stainless Steels During Hot Rolling, Z Y. Jiang, D B. Wei, K Tieu, J X. Huang, A W. Zhang, X Shi, S H. Jiao Jan 2011

Study On Oxidation Of Stainless Steels During Hot Rolling, Z Y. Jiang, D B. Wei, K Tieu, J X. Huang, A W. Zhang, X Shi, S H. Jiao

Faculty of Engineering and Information Sciences - Papers: Part A

The oxidation of stainless steels 304 and 304L during hot rolling is studied in this paper. Results show the oxide scale thickness decreases significantly with an increase of reduction, and the oxide scales of both 304 and 304L stainless steels were found more deformable than the steel substrate. Surface roughness shows a complicated transfer during the hot rolling process due to the complexity of oxide scale characteristics. Also, surface roughness decreases with an increase of reduction. The friction coefficient increases with reduction in all cases, and the increase is more significant in the case of the 304 stainless steel than …


Mechanical Property Development During Uoe Forming Of Large Diameter Pipeline Steels, Andrii Kostryzhev, Martin Strangwood, Claire L. Davis Jan 2010

Mechanical Property Development During Uoe Forming Of Large Diameter Pipeline Steels, Andrii Kostryzhev, Martin Strangwood, Claire L. Davis

Faculty of Engineering and Information Sciences - Papers: Part A

Mechanical properties of large diameter welded steel pipes depend on the thermomechanically controlled rolled (TMCR) plate microstructure and UOE pipe-forming cold deformation sequence. Strength from plate to pipe may increase (work-hardening) or decrease (the Bauschinger effect). Bauschinger effect parameters depend on steel composition and plate processing history. The present study is examining two pipeline grades: X60 (Nb-alloyed) and X65 (Nb- and V-alloyed). Mechanical properties are determined by grain refinement, solid solution, precipitation strengthening mechanisms, and work-hardening (work-softening). The reverse deformation yield drop increases with an increase in the precipitate particle volume fraction and pre-strain. Annealing, leading to a decrease in …


Flicker Mitigation Strategy For Dfigs During Variable Wind Conditions, Lasantha Meegahapola, Brendan Fox, Damian Flynn Jan 2010

Flicker Mitigation Strategy For Dfigs During Variable Wind Conditions, Lasantha Meegahapola, Brendan Fox, Damian Flynn

Faculty of Engineering and Information Sciences - Papers: Part A

This paper presents a flicker mitigation scheme for the doubly-fed induction generator (DFIG) during variable wind conditions. The flicker mitigation strategy was developed based on the distribution line X/R ratio and the active power deviation from the average active power during variable wind conditions. Flicker emission was analyzed using a flicker meter based on the IEC standards. Both short-term and long-term flicker severities were analyzed during the time period of study. The flicker mitigation strategy was evaluated under different system conditions such as X/R ratio, distribution line length, shortcircuit capacity (SCC), and wind variability. It is shown that the proposed …


Observations Of Decomposition Of Martensite During Heat Treatment Of Steels Using Atom Probe Tomography, Elena V. Pereloma, Simon Peter Ringer, Ilana B. Timokhina, Peter D. Hodgson Jan 2009

Observations Of Decomposition Of Martensite During Heat Treatment Of Steels Using Atom Probe Tomography, Elena V. Pereloma, Simon Peter Ringer, Ilana B. Timokhina, Peter D. Hodgson

Faculty of Engineering and Information Sciences - Papers: Part A

The decomposition of martensite during tempering or ageing is an important phenomenon as it leads to changes in the mechanical properties. These changes could take place during both steel manufacturing or in-service. Thus, their understanding is required to predict the material performance. Recent advances in the development of local electrode atom probes has led to a significant increase in the analysed volume of material (up to 100 millions of atoms) and at the same time reduced the acquisition times. This allows improvement in data statistics when investigating fine nanoscale features, such as solute segregation, clustering and ultrafine precipitation. Selected results …


Effects Of Shoe Heel Height On Loading And Muscle Activity For Trans-Tibial Amputees During Standing, Xiaohong Jia, Rencheng Wang, Winson Lee Jan 2009

Effects Of Shoe Heel Height On Loading And Muscle Activity For Trans-Tibial Amputees During Standing, Xiaohong Jia, Rencheng Wang, Winson Lee

Faculty of Engineering and Information Sciences - Papers: Part A

This study accesses the effects of shoe heel heights on loading, muscle activity, and plantar foot pressure of trans-tibial amputees during standing. Five male subjects with unilateral trans-tibial amputation volunteered to participate in this study. Three pairs of shoes with zero, 20 mm, and 40 mm heel heights were used. The loading line of the prosthetic side, the plantar foot pressure, and the surface electromyography (EMG) of 10 muscles were simultaneously recorded. With increasing shoe heel heights during standing, the loading line of the prosthetic side shifted from the anterior to the posterior side of the knee center, the peak …


Influence Of Edge Rolling Reduction On Plate-Edge Stress Distribution During Finish Rolling, Hai-Liang Yu, Xiang-Hua Liu, Li-Qing Chen, Chang-Sheng Li, Ying Zhi, Xin-Wen Li Jan 2009

Influence Of Edge Rolling Reduction On Plate-Edge Stress Distribution During Finish Rolling, Hai-Liang Yu, Xiang-Hua Liu, Li-Qing Chen, Chang-Sheng Li, Ying Zhi, Xin-Wen Li

Faculty of Engineering and Information Sciences - Papers: Part A

Dimensions of one kind of stainless steel plate before finish rolling were obtained through analysis of the rough rolling processes by finite element method and updated geometrical method. The FE models of finish rolling process with a front edge roll were built, and influences of the edge rolling reduction on the stress change in the plate edge during finish rolling were analyzed. The results show that when the edge rolling reduction is increased from 0 mm to 2 mm, the compressive stress in plate corner clearly increases in edge rolling process, and the zone of tensile stress during whole rolling …


Influence Of Microalloying Precipitates On Bauschinger Effect During Uoe Forming Of Line Pipe Steels, Andrii Kostryzhev, Martin Strangwood, Claire L. Davis Jan 2007

Influence Of Microalloying Precipitates On Bauschinger Effect During Uoe Forming Of Line Pipe Steels, Andrii Kostryzhev, Martin Strangwood, Claire L. Davis

Faculty of Engineering and Information Sciences - Papers: Part A

Large diameter steel line pipes are generally produced by cold deforming hot rolled or thermomechanically controlled rolled (TMCR) plate by the three-stage 'UOE' process. Pipe strength has been found to increase or decrease relative to the plate, depending on the steel grade and plate processing history. The strength increase is due to work hardening whereas any decrease in strength arises from the Bauschinger effect due to the reverse cold deformation of the UOE process. The steel chemistry, through the presence of strengthening microalloy precipitates, and prior processing, through the size and distribution of microalloy precipitates and the presence of retained …


Numerical Simulation Of Temperature Field And Thermal Stress Field Of Work Roll During Hot Strip Rolling, Chang-Sheng Li, Hai-Liang Yu, Guan-Yu Deng, Xiang-Hua Liu, Guo-Dong Wang Jan 2007

Numerical Simulation Of Temperature Field And Thermal Stress Field Of Work Roll During Hot Strip Rolling, Chang-Sheng Li, Hai-Liang Yu, Guan-Yu Deng, Xiang-Hua Liu, Guo-Dong Wang

Faculty of Engineering and Information Sciences - Papers: Part A

Based on the thermal conduction equations, the three-dimensional (3D) temperature field of a work roll was investigated using finite element method (FEM). The variations in the surface temperature of the work roll during hot strip rolling were described, and the thermal stress field of the work roll was also analyzed. The results showed that the highest roll surface temperature is 593 °C, and the difference between the minimum and maximum values of thermal stress of the work roll surface is 145. 7 MPa. Furthermore, the results of this analysis indicate that temperature and thermal stress are useful parameters for the …


Influence Of Dog-Bone Apex On Shape During Slab Horizontal Rolling Process, Hai-Liang Yu, Xiang-Hua Liu, Chang-Sheng Li, Guo-Dong Wang Jan 2007

Influence Of Dog-Bone Apex On Shape During Slab Horizontal Rolling Process, Hai-Liang Yu, Xiang-Hua Liu, Chang-Sheng Li, Guo-Dong Wang

Faculty of Engineering and Information Sciences - Papers: Part A

The deformation of slab with dog-bone shape during the horizontal rolling process was simulated using FEM, and the influences of apical dislocation of dog-bone on the slab spread as well as the minimum crop end loss and the lost width at slab head and tail were analyzed. The results show that with the increase in the apical dislocation of dog-bone (LA), the slab spread and the minimum crop end loss at slab head and tail decrease, while the lost width at slab head and tail increases. Meanwhile, the relationships of S/LA-LA, LH/LA-LA, WH/LA-LA, LT/LA-LA, and WT/LA-LA were obtained. © 2007 …


Behavior Of Transversal Crack On Slab Corner During V-H Rolling Process, Hai-Liang Yu, Xiang-Hua Liu, Chang-Sheng Li, Y Kusaba Jan 2006

Behavior Of Transversal Crack On Slab Corner During V-H Rolling Process, Hai-Liang Yu, Xiang-Hua Liu, Chang-Sheng Li, Y Kusaba

Faculty of Engineering and Information Sciences - Papers: Part A

The behavior of transversal cracks on the surface of the slab corner during vertical and horizontal (V-H) rolling process with flat vertical roll and groove vertical roll was simulated by explicit dynamic finite element method. The closure and growth of crack and the contact pressure on surfaces of the crack in contacting zone between slab and roll during rolling process were analyzed. The results showed that during vertical rolling process, when the groove vertical roll is used, the maximum contact pressure on surfaces of the crack is 115 MPa, and the closure of crack is stable; when the flat vertical …


A Quasi-Dynamic Nonlinear Finite Element Model To Investigate Prosthetic Interface Stresses During Walking For Trans-Tibial Amputees, Xiaohong Jia, Ming Zhang, Xiaobing Li, Winson Lee Jan 2005

A Quasi-Dynamic Nonlinear Finite Element Model To Investigate Prosthetic Interface Stresses During Walking For Trans-Tibial Amputees, Xiaohong Jia, Ming Zhang, Xiaobing Li, Winson Lee

Faculty of Engineering and Information Sciences - Papers: Part A

Background. To predict the interface pressure between residual limb and prosthetic socket for trans-tibial amputees during walking. Methods. A quasi-dynamic finite element model was built based on the actual geometry of residual limb, internal bones and socket liner. To simulate the friction/slip boundary conditions between the skin and liner, automated surface-to-surface contact was used. Besides variable external loads and material inertia, the coupling between the large rigid displacement of knee joint and small elastic deformation of residual limb and prosthetic components were also considered. Results. Interface pressure distribution was found to have the same profile during walking. The high pressures …