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Effect Of Grain Size On The Hydrogen Diffusion Process In Steel Using Cellular Automaton Approach, Druce P. Dunne, E V. Pereloma, Nima Yazdipour
Effect Of Grain Size On The Hydrogen Diffusion Process In Steel Using Cellular Automaton Approach, Druce P. Dunne, E V. Pereloma, Nima Yazdipour
Faculty of Engineering - Papers (Archive)
The role of microstructure in susceptibility to hydrogen uptake and property degradation is being evaluated using a number of high strength pipeline steels. To do so, a cellular automaton (CA) model has been used to examine the effect of grain size, as a first step in assessing the influence of microstructure. The simulation results of hydrogen diffusion into microstructures with different grain sizes are presented.
Net Section Tension Capacity Of Bolted Connections In Cold-Reduced Steel Sheets, Lip H. Teh, Benoit P. Gilbert
Net Section Tension Capacity Of Bolted Connections In Cold-Reduced Steel Sheets, Lip H. Teh, Benoit P. Gilbert
Faculty of Engineering - Papers (Archive)
This paper examines the accuracy of design equations specified in the North American, European and Australasian codes for coldformed steel structures in determining the net section tension capacity of bolted connections in flat steel sheets. It points out that the shear lag factors embedded in the code equations either yield “anomalous” results or become irrelevant when they exceed unity. The “anomaly” was demonstrated through laboratory tests and is explained by using simple calculus. The configurations of specimens tested in the laboratory include single shear- and double-shear connections, with single or double bolts in a line parallel or perpendicular to the …
Inelastic Stability Analysis Of High Strength Rectangular Concrete-Filled Steel Tubular Slender Beam-Columns, Vipulkumar Ishvarbhai Patel, Qing Quan Liang, Muhammad N. S Hadi
Inelastic Stability Analysis Of High Strength Rectangular Concrete-Filled Steel Tubular Slender Beam-Columns, Vipulkumar Ishvarbhai Patel, Qing Quan Liang, Muhammad N. S Hadi
Faculty of Engineering - Papers (Archive)
There is relatively little numerical study on the behavior of eccentrically loaded high strength rectangular concrete-filled steel tubular (CFST) slender beam-columns with large depth-to-thickness ratios, which may undergo local and global buckling. This paper presents a multi scale numerical model for simulating the interaction local and global buckling behavior of hlgh strength thin-walled rectangular CFST slender beam-columns under eccentric loading. The effects of progressive local buckling are taken into account in the mesoscale model based on fiber element formulations. Computational algorithms based on the Muller's method are developed to obtain complete load-deflection responses of CFST slender beam-columns at the macroscale …
Block Shear Capacity Of Bolted Connections In Cold-Reduced Steel Sheets, Lip H. Teh, Drew D. A Clements
Block Shear Capacity Of Bolted Connections In Cold-Reduced Steel Sheets, Lip H. Teh, Drew D. A Clements
Faculty of Engineering - Papers (Archive)
This paper examines the mechanisms for block shear failures of bolted connections in steel plates postulated in the design equations specified in the North American, European and Australian steel structures codes. It explains that there is only one feasible mechanism for the limit state of conventional block shear failure, that which involves tensile rupture and shear yielding, irrespective of the steel material ductility. It describes the fundamental shortcomings of various code equations for determining the block shear capacity of a bolted connection. Based on the tensile rupture and shear yielding mechanism, an in-plane shear lag factor, and the active shear …
Precipitation Behavior Of Magnetite In Oxide Scale During Cooling Of Microalloyed Low Carbon Steel, Xianglong Yu, Zhengyi Jiang, Daijun Yang, Dongbin Wei, Quan Yang
Precipitation Behavior Of Magnetite In Oxide Scale During Cooling Of Microalloyed Low Carbon Steel, Xianglong Yu, Zhengyi Jiang, Daijun Yang, Dongbin Wei, Quan Yang
Faculty of Engineering - Papers (Archive)
Precipitation behavior of magnetite particles in the thermal grown oxide scale during isothermal cooling of microalloyed low carbon steel was studied using scanning electron microscopy (SEM) and thin film X-ray. The oxide scale was generated from Gleeble 3500 Thermal-Mechanical Simulator connected with a humid air generator, to simulate 550 and 450°C isothermal treatments. Several types of magnetite precipitates were observed during different cooling processes with respect to the possible mechanisms of precipitation have been discussed. It is found that magnetite particles is as a result of pro-eutectoid precipitation from oxygen-rich wustite, and also as a product of the partial decomposition …
Microstructure And Mechanical Properties Of If Steel Deformed During Plane Stress Local Torsion, A H. Shamdani, S Khoddam, P F. Thomson, A Dehghan-Manshadi
Microstructure And Mechanical Properties Of If Steel Deformed During Plane Stress Local Torsion, A H. Shamdani, S Khoddam, P F. Thomson, A Dehghan-Manshadi
Faculty of Engineering - Papers (Archive)
Mechanical joints are inherently vulnerable to failure because the presence of the joint hole causes a stress concentration in the vicinity of the hole. The need for improvement of material strength around a fastener hole can be satisfied by severe plastic deformation (SPD) to produce ultrafine grains. The ultrafine grained (UFG) alloys produced by SPD processing possess higher strengths than their coarse-grained counterparts as a result of the reduced grain size. However, in some circumstances such as SPD processing of Al-Zn and Al-Mg alloys the decomposition of supersaturated solid solutions competes with the Hall-Petch effect and leads to a more …
Experimental Study On Adhesion Of Oxide Scale On Hot-Rolled Steel Strip, Xianglong Yu, Dongbin Wei, Xiaodong Wang, Zhengyi Jiang
Experimental Study On Adhesion Of Oxide Scale On Hot-Rolled Steel Strip, Xianglong Yu, Dongbin Wei, Xiaodong Wang, Zhengyi Jiang
Faculty of Engineering - Papers (Archive)
An experimental method was developed to study the adherence properties of the oxide scale formed on microalloyed low carbon steel after hot strip rolling. The evolution of the oxide scale during laminar cooling was investigated using Gleeble 3500 Thermal-Mechanical Simulator connected with a humid air generator. After the sample cooled down to ambient temperature, the oxide scale was protected by lacquer to prevent the scale from losing. Physicochemical characteristics of the oxide scale were examined and the adherence mechanism was discussed. Decomposed wustite a mixture of α-iron and magnetite (Fe3O4), can substantially improve the integrity of …
A Novel Laboratory Technique For Introducing Inclusion To Liquid Steel, Neslihan Dogan, Brian J. Monaghan, Raymond J. Longbottom, Mark H. Reid, Xenophon C. Tsekouras
A Novel Laboratory Technique For Introducing Inclusion To Liquid Steel, Neslihan Dogan, Brian J. Monaghan, Raymond J. Longbottom, Mark H. Reid, Xenophon C. Tsekouras
Faculty of Engineering - Papers (Archive)
Previous studies in steel cleanness have been hampered by limited control of inclusions’ phase and composition. This limited control is often a result of studying inclusion formation and development using industrial steel melts and the inclusions therein as starting material. This is an extremely complex situation and not always readily amenable to analysis. A new experimental laboratory technique has been developed that allows addition of inclusions of known, size, phase and composition to be added to liquid steel. These inclusions can then be tracked and changes in morphology with time can be assessed for different melt conditions. The technique involves …
Self-Shape Optimisation Application: Optimisation Of Cold-Formed Steel Columns, Benoit P. Gilbert, Timothee J-M Savoyat, Lip H. Teh
Self-Shape Optimisation Application: Optimisation Of Cold-Formed Steel Columns, Benoit P. Gilbert, Timothee J-M Savoyat, Lip H. Teh
Faculty of Engineering - Papers (Archive)
This paper presents the optimisation of cold-formed steel open columns using the recently developed self-shape optimisation method that aims to discover new profile shapes. The strength of the coldformed steel sections is calculated using the Direct Strength Method, and the rules developed in the present work to automatically determine the local and distortional elastic buckling stresses from the Finite Strip and constrained Finite Strip Methods are discussed. The rules are verified against conventional and optimum sections yielded in this research, and found to accurately predict the elastic buckling stresses. The optimisation method is applied to singly-symmetric (mono-symmetric) cold-formed steel columns, …
Modelling Of Temperature-Dependent Growth Kinetics Of Oxide Scale On Hot-Rolled Steel Strip, Xianglong Yu, Zhengyi Jiang, Dongbin Wei, Xiaodong Wang, Quan Yang
Modelling Of Temperature-Dependent Growth Kinetics Of Oxide Scale On Hot-Rolled Steel Strip, Xianglong Yu, Zhengyi Jiang, Dongbin Wei, Xiaodong Wang, Quan Yang
Faculty of Engineering - Papers (Archive)
A numerical simulation, developed to predict the temperature distribution and calculate the growth rale of the oxide scale formed on the microalloyed low carbon steel during the laminar cooling of hot strip rolling, was conducted by two-dimensional finite element method. The model takes into account the different thetmoPhYsical properties of the multilayered oxide scales and the film boundary conditions for the water jet impingement zone and the stable film boiling zone through the run-out table. Complied with the parabolic growth of the oxide layers and the distribution of the oxide phase, it is found that the present of wustite (FeO) …
Tension Capacity Of Staggered Bolted Connections In Cold-Reduced Steel Sheets, Lip H. Teh, Drew D. A Clements
Tension Capacity Of Staggered Bolted Connections In Cold-Reduced Steel Sheets, Lip H. Teh, Drew D. A Clements
Faculty of Engineering - Papers (Archive)
This paper examines the assumption implicit in Cochrane’s formula that stresses are uniformly distributed across the net section of a staggered bolted connection. The assumption was found to be overoptimistic for connections in steel having low ductility, leading to unconservative estimates for the tension capacity if the in-plane shear lag is not accounted for. The reduction factor of 0.9 specified in the North American specification for cold-formed steel structures partially but not wholly addresses the problems inherent in the code equations. This paper points out that the “simplification” of Cochrane’s original formula into the standard formula used in steel design …
Effect Of Annealing On The Microstructure, Texture And Mechanical Properties Of Severely Deformed Interstitial Free Steel, Sujoy S. Hazra, Azdiar A. Gazder, E V. Pereloma
Effect Of Annealing On The Microstructure, Texture And Mechanical Properties Of Severely Deformed Interstitial Free Steel, Sujoy S. Hazra, Azdiar A. Gazder, E V. Pereloma
Faculty of Engineering - Papers (Archive)
Ti-stabilised interstitial free (IF) steel initially subjected to 8 passes, route BC equal channel angular pressing (ECAP) was further cold rolled (CR) at room temperature to 95% thickness reduction. Both samples were isothermally annealed at 710 °C following which their microstructures and micro-textures were compared via electron back-scattering diffraction (EBSD). The mechanical properties first obtained by shear punch testing (SPT) were later corroborated by uniaxial tensile tests. In the case of the ECAP material, continuous recrystallisation is followed by abnormal growth at prolonged annealing times with minor increases in high angle boundary (HAGB) fraction. On the other hand, the …
Effect Of Ti And N Concentrations On Microstructure And Mechanical Properties Of Microalloyed High Strength Line Pipe Steel Welds, Leigh Fletcher, Zhixiong Zhu, Marimuthu Murugananth, Lei Zheng, Mingzhuo Bai, Huijun Li, F Barbaro
Effect Of Ti And N Concentrations On Microstructure And Mechanical Properties Of Microalloyed High Strength Line Pipe Steel Welds, Leigh Fletcher, Zhixiong Zhu, Marimuthu Murugananth, Lei Zheng, Mingzhuo Bai, Huijun Li, F Barbaro
Faculty of Engineering - Papers (Archive)
A selection of nine heats of line pipe steel from the same project with different Ti and N content were used to evaluate the effects of Ti/N ratio on weld zone microstructure, hardness and prior austenite grain size (PAGS) in the coarse grained heat-affected zone (CGHAZ). It was shown that the microstructure of the base metal (BM) mainly consisted of fine grained polygonal ferrite with fine islands of pearlite. The weld metal (WM) microstructure was predominantly acicular ferrite with a small volume fraction of pro-eutectoid ferrite. The CGHAZ consisted of bainitic ferrite and islands of martensite-austenite. The inside region of …
Rehabilitating Destructed Reinforced Concrete T Connections By Steel Straps, Muhammad N. S Hadi
Rehabilitating Destructed Reinforced Concrete T Connections By Steel Straps, Muhammad N. S Hadi
Faculty of Engineering - Papers (Archive)
The aim of this paper is to present results of testing a full scale reinforced concrete T connection by static loading. The connection represents a beam-column connection. The beam and column had a square cross section with a 300 mm dimension. The height of the column was 2.9 m and the clear beam length was 1.4 m. The connection was initially tested to failure. Galvanised steel straps were used to rehabilitate the connection. Epoxy resin was used to fix the steel straps to the concrete surface. The connection was tested after the rehabilitation. Results of testing the rehabilitated connection show …
The Influence Of Copper Content Of Welding Wires On The Fume Formation Rates In Gas Metal Arc Welding Of Steel, N Bothma, B J. Monaghan, J Norrish
The Influence Of Copper Content Of Welding Wires On The Fume Formation Rates In Gas Metal Arc Welding Of Steel, N Bothma, B J. Monaghan, J Norrish
Faculty of Engineering - Papers (Archive)
Increases in Fume Formation Rates (FFR) of welding wires have been attributed to the fact that wires are copper coated. Instability during the welding process can have an influence on the FFR. The University of Wollongong has developed an auto control mechanism that will minimise the influence of the instability and this could be applied to more accurately determine the FFR of welding wires in the "drop-spray" mode of transfer.
Microstructure And Mechanical Properties After Annealing Of Equal-Channel Angular Pressed Interstitial-Free Steel, Sujoy S. Hazra, Elena V. Pereloma, Azdiar A. Gazder
Microstructure And Mechanical Properties After Annealing Of Equal-Channel Angular Pressed Interstitial-Free Steel, Sujoy S. Hazra, Elena V. Pereloma, Azdiar A. Gazder
Faculty of Engineering - Papers (Archive)
The evolution of microstructure, microtexture and mechanical properties during isothermal annealing of an ultrafine-grained interstitial-free steel after eight passes of route BC room temperature equal-channel angular pressing (ECAP) was studied. The microstructure and microtexture were characterized by electron back-scattering diffraction, and mechanical properties were assessed by shear punch and uniaxial tensile testing. Homogeneous coarsening via continuous recrystallization of the ECAP microstructure is accompanied by minor changes in the ∼63% high-angle boundary population and a sharpening of the original ECAP texture. This is followed by abnormal growth during the final stages of softening due to local growth advantages. Linear correlations …
A Study Of The Continous Cooling Behaviour And Effect Of Preheat And Interpass Temperature On The Haz Of High Strength Quenched And Tempered Steel, Lenka Kuzmikova, Mark Callaghan, Nathan Larkin, Robert Scott, Robert De Jong, Huijun Li, John Norrish
A Study Of The Continous Cooling Behaviour And Effect Of Preheat And Interpass Temperature On The Haz Of High Strength Quenched And Tempered Steel, Lenka Kuzmikova, Mark Callaghan, Nathan Larkin, Robert Scott, Robert De Jong, Huijun Li, John Norrish
Faculty of Engineering - Papers (Archive)
In this study, the continuous cooling phase transformation behaviour of a quenched and tempered armour steel was investigated. A continuous cooling transformation diagram was constructed providing valuable information for predicting microstructural evolution and mechanical properties at different cooling rates during actual welding fabrication. Welding trials were carried out utilising flux-cored arc welding technique in combination with an austenitic stainless steel consumable. The effect of various preheat and interpass temperatures on cooling rate and consequently on the heat affected zone microstructure and mechanical properties of multipass welds were investigated.
Mechanical, Microstructure And Texture Properties Of Interstitial-Free Steel And Copper Subjected To Equal Channel Angular Extrusion And Cold-Rolling, A A. Gazder, S S. Hazra, C F. Gu, W Q. Cao, C H J Davies, E V. Pereloma
Mechanical, Microstructure And Texture Properties Of Interstitial-Free Steel And Copper Subjected To Equal Channel Angular Extrusion And Cold-Rolling, A A. Gazder, S S. Hazra, C F. Gu, W Q. Cao, C H J Davies, E V. Pereloma
Faculty of Engineering - Papers (Archive)
Interstitial-free steel and OFHC copper were subjected to 8 passes, route BC room temperature ECAE followed by cold-rolling up to 97.5% thickness reduction. Uniaxial tensile tests and Electron Back-Scattering Diffraction were used to characterise the evolution in mechanical properties, microstructure refinement and micro-texture. IF-steel showed continuous increase in strength whereas Cu returned reduced strength and a small gain in ductility at 97.5% reduction. In both metals substructure refinement was accompanied by an increase in high-angle boundary fraction, average misorientation and a slight increase in Σ3 boundaries. An evolution of crystallographic orientations from negative shear to predominantly cold-rolled textures after …
Role Of Microstructure In Susceptibility Of X70 Pipeline Steel To Hydrogen Embrittlement, Daniel Hejazi, Ayesha J. Haq, Nima Yazdipour, Druce P. Dunne, F Barbaro, E V. Pereloma
Role Of Microstructure In Susceptibility Of X70 Pipeline Steel To Hydrogen Embrittlement, Daniel Hejazi, Ayesha J. Haq, Nima Yazdipour, Druce P. Dunne, F Barbaro, E V. Pereloma
Faculty of Engineering - Papers (Archive)
In order to investigate the susceptibility of steels to hydrogen embrittlement as a function of their microstructure X70 steel was chosen in different conditions: normalized transfer bar, as-received hot rolled strip and heat affected zone (HAZ). Notched and fatigue pre-cracked samples were subjected to electrochemical hydrogen charging to achieve 2 ppm hydrogen content. Three point bend tests were conducted on as-received and hydrogen charged samples. The results showed that HAZ samples are more susceptible to hydrogen embrittlement than the others. This was supported by fracture surface observations.
Influence Of Shielding Gas On Fume Formation Rate For Gas Metal Arc Welding (Gmaw) Of Plain Carbon Steel, Kristin R. Carpenter, Brian J. Monaghan, John Norrish
Influence Of Shielding Gas On Fume Formation Rate For Gas Metal Arc Welding (Gmaw) Of Plain Carbon Steel, Kristin R. Carpenter, Brian J. Monaghan, John Norrish
Faculty of Engineering - Papers (Archive)
Shielding gas composition is an important parameter for successful gas metal arc welding (GMAW) and has been shown to affect the fume formation rate (FFR). The present paper compares thirteen shielding gases and their impact on FFR in spray transfer. In Ar-based mixtures, increasing CO2 had a greater impact than raising O2 on FFR. When O2 was increased in ternary mixtures, the FFR increased for Ar-5%CO2 but no discernable increase was observed for the Ar-12%CO2 mixtures. Ar-He-CO2 mixtures had the most stable FFR's. The FFR for 100% CO2 was significantly higher due to the change in weld transfer mode to …
Analysis Of Fume Formation Rate And Fume Particle Composition For Gas Metal Arc Welding (Gmaw) Of Plain Carbon Steel Using Different Shielding Gas Compositions, Kristin R. Carpenter, Brian J. Monaghan, John Norrish
Analysis Of Fume Formation Rate And Fume Particle Composition For Gas Metal Arc Welding (Gmaw) Of Plain Carbon Steel Using Different Shielding Gas Compositions, Kristin R. Carpenter, Brian J. Monaghan, John Norrish
Faculty of Engineering - Papers (Archive)
The present paper compares thirteen shielding gases and their impact on FFR and fume particle while welding in the spray transfer regime. There was no obvious influence from the shielding gas on particle composition and fume particles were identified as (Fe,Mn)3O4. There was a slight peak shift that indicated that small levels of Mn, as detected by TEM-EDS, substituted for Fe in the Fe3O4 phase. Shielding gas composition is an important parameter for successful gas metal arc welding (GMAW) and has been shown to affect the fume formation rate (FFR). In Ar-based mixtures, increasing CO2 had a greater impact than …
Response Of Rigid Polyurethane Foam-Filled Steel Hollow Columns Under Low Velocity Impact, Alexander Remennikov, Brian Uy, Kong Sih Ying
Response Of Rigid Polyurethane Foam-Filled Steel Hollow Columns Under Low Velocity Impact, Alexander Remennikov, Brian Uy, Kong Sih Ying
Faculty of Engineering - Papers (Archive)
This paper presents the results of experimental investigations on rigid polyurethane foam-filled steel hollow columns under dynamic loading conditions.
Microstructure And Mechanical Properties Of Thermomechanically Processed Trip Steel, Ilana B. Timokhina, Peter D. Hodgson, Hossein Beladi, E V. Pereloma
Microstructure And Mechanical Properties Of Thermomechanically Processed Trip Steel, Ilana B. Timokhina, Peter D. Hodgson, Hossein Beladi, E V. Pereloma
Faculty of Engineering - Papers (Archive)
The strengthening mechanism responsible for the unique combination of ultimate tensile strength and elongation in a multiphase Fe-0.2C-1.5Mn-1.2Si-0.3Mo-0.6Al-0.02Nb (wt%) steel was studied. The microstructures with different volume fractions of polygonal ferrite, bainite and retained austenite were simulated by controlled thermomechanical processing. The interrupted tensile test was used to study the bainitic ferrite, retained austenite and polygonal ferrite behaviour as a function of plastic strain. X-ray analysis was used to characterise the volume fraction and carbon content of retained austenite. Transmission electron microscopy was utilised to analyse the effect of bainitic ferrite morphology on the strain induced transformation of retained austenite …
Behaviour Of Eccentric Loading Of Frp Confined Fibre Steel Reinforced Concrete Columns, Muhammad N. S Hadi
Behaviour Of Eccentric Loading Of Frp Confined Fibre Steel Reinforced Concrete Columns, Muhammad N. S Hadi
Faculty of Engineering - Papers (Archive)
This paper presents results of testing 16 specimens, 12 of which as columns under different eccentricitiesand four as beams under four point loading regime. All 16 specimens were circular in cross section andwere made of reinforced concrete. Four specimens served as reference specimens and were just made ofreinforced concrete. The next four specimens were wrapped with carbon fibre reinforced polymers(CFRP). The next four specimens had steel fibres added to the concrete. The final four specimens werereinforced with steel fibres and wrapped with CFRP. From each group of specimens, one specimen wastested as a column under a concentric load, the second …
Observation Of Precipitation Evolution In Fe-Ni-Mn-Ti-Al Maraging Steel By Atom Probe Tomography, E V. Pereloma, R.A. Stohr, M.K Miller, S P. Ringer
Observation Of Precipitation Evolution In Fe-Ni-Mn-Ti-Al Maraging Steel By Atom Probe Tomography, E V. Pereloma, R.A. Stohr, M.K Miller, S P. Ringer
Faculty of Engineering - Papers (Archive)
We describe the full decomposition sequence in an Fe-Ni-Mn-Ti-Al maraging steel during isothermal annealing at 550 °C. Following significant pre-precipitation clustering reactions within the supersaturated martensitic solid solution, (Ni,Fe)3Ti and (Ni,Fe)3(Al,Mn) precipitates eventually form after isothermal aging for ~60 seconds. The morphology of the (Ni,Fe)3Ti particles changes gradually during aging from predominantly plate-like to rod-like, and, importantly, Mn and Al were observed to segregate to these precipitate/matrix interfaces. The (Ni,Fe)3(Al,Mn) precipitates occurred at two main locations: uniformly within the matrix and at the periphery of the (Ni,Fe)3Ti particles. We relate …
Hot Deformation And Recrystallization Of Austenitic Stainless Steel. Part I: Dynamic Recrystallization, A Dehghan-Manshadi, Mathew R. Barnett, P D. Hodgson
Hot Deformation And Recrystallization Of Austenitic Stainless Steel. Part I: Dynamic Recrystallization, A Dehghan-Manshadi, Mathew R. Barnett, P D. Hodgson
Faculty of Engineering - Papers (Archive)
The hot deformation behavior of a 304 austenitic stainless steel was investigated to characterize the evolution of the dynamically recrystallized structure as a starting point for studies of the postdeformation recrystallization behavior. The effect of different deformation parameters such as strain, strain rate, and temperature were investigated. The flow curves showed typical signs of dynamic recrystallization (DRX) over a wide range of temperatures and strain rates (i.e., different Zener–Hollomon (Z) values). However, under very high or very low Z values, the flow curves’ shapes changed toward those of the dynamic recovery and multiple peaks, respectively. The …
Hot Deformation And Recrystallization Of Austenitic Stainless Steel. Part Ii: Post-Deformation Recrystallization, A Dehghan-Manshadi, Mathew R. Barnett, P D. Hodgson
Hot Deformation And Recrystallization Of Austenitic Stainless Steel. Part Ii: Post-Deformation Recrystallization, A Dehghan-Manshadi, Mathew R. Barnett, P D. Hodgson
Faculty of Engineering - Papers (Archive)
The postdeformation recrystallization behavior of a hot-deformed austenitic stainless steel was investigated based on the first part of this study, in which the microstructure development during hot deformation and, in particular, the evolution of dynamic recrystallization (DRX), was studied. The effect of different parameters such as strain, strain rate, and temperature were examined. The dependency of the time for 50 pct softening, t 50, changed from “strain dependent” to “strain independent” at a transition strain (ε*) that was in the steady-state area of the hot deformation flow curve. The fully recrystallized microstructure showed a similar transition in …
Effect Of Processing Schedule On The Microstructure And Texture Of 0.78wt% Cr Extra-Low-Carbon Steel, Elena V. Pereloma, Azdiar A. Gazder, John J. Jonas, Michael K. Miller, Christopher Hj Davies
Effect Of Processing Schedule On The Microstructure And Texture Of 0.78wt% Cr Extra-Low-Carbon Steel, Elena V. Pereloma, Azdiar A. Gazder, John J. Jonas, Michael K. Miller, Christopher Hj Davies
Faculty of Engineering - Papers (Archive)
An extra-low-carbon steel was alloyed with 0.78 wt% Cr and subjected to three different processing schedules involving: (i) warm rolling to 65 % reduction at 640°C, (ii) warm rolling to 80% reduction at 580°C and (iii) warm rolling to 65% reduction at 640°C followed by cold rolling to 40% reduction. Increasing the severity of the deformation resulted in an increase in the number of grains containing in-grain shear bands. X-ray bulk texture analysis indicates that the g -fibre intensity was slightly higher in the steel warm rolled at 580°C than at 640°C and after cold rolling. Transmission electron microscopy and …
An Ebsd Investigation Of Interstitial-Free Steel Subjected To Equal Channel Angular Extrusion, Azdiar A. Gazder, Wenquan Q. Cao, Christopher H.J. Davies, E V. Pereloma
An Ebsd Investigation Of Interstitial-Free Steel Subjected To Equal Channel Angular Extrusion, Azdiar A. Gazder, Wenquan Q. Cao, Christopher H.J. Davies, E V. Pereloma
Faculty of Engineering - Papers (Archive)
The microstructural evolution of interstitial-free (IF) steel subjected to Φ = 90° equal channel angular extrusion (ECAE) for up to 4 passes via routes A, BA, C and up to 8 passes via routes BC was studied using electron back-scattering diffraction (EBSD). Routes BC and BA recorded the smallest grain size and aspect ratios and the largest average misorientation and area fraction of high-angle grain boundaries (HAGBs). During multiple passes, microstructure refinement continues until a convergence in effective subgrain and grain diameters occurs; following which the rate of HAGB formation reduces slightly. The percentage rise …
Nonlinear Analysis And Behavior Of Concrete-Filled Steel Tubular Beam-Columns, Qing Quan Liang, Muhammad N. S Hadi
Nonlinear Analysis And Behavior Of Concrete-Filled Steel Tubular Beam-Columns, Qing Quan Liang, Muhammad N. S Hadi
Faculty of Engineering - Papers (Archive)
This paper presents a nonlinear fiber element analysis method for predicting the behavior of short concrete-filled steel tubular (CFST) beam-columns under axial load and biaxial bending. Nonlinear constitutive models for confined concrete and structural steel are considered in the fiber element analysis. Efficient secant algorithms are developed to iterate the depth and orientation of the neutral axis within the composite section to satisfy equilibrium conditions. The accuracy of the fiber element method is established by comparisons with existing solutions. The fiber element analysis program developed is employed to study the effects of steel ratios and concrete strengths on the axial …