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Full-Text Articles in Engineering
Sensitization Behaviour Of 11-12% Cr Aisi 409 Stainless Steel During Low Heat Input Welding, Cornelis Janise Van Niekerk, Madeleine Du Toit
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 …
Development Of A Dc-Lsnd Welding Process For Gmaw On Dh-36 Steel, Raymond Holder, Nathan Larkin, Huijun Li, Lenka Kuzmikova, Zengxi Pan, John Norrish
Development Of A Dc-Lsnd Welding Process For Gmaw On Dh-36 Steel, Raymond Holder, Nathan Larkin, Huijun Li, Lenka Kuzmikova, Zengxi Pan, John Norrish
Faculty of Engineering and Information Sciences - Papers: Part A
Weld induced distortion correction is a major cost within the shipbuilding industry. This paper investigates the use of an active cooling process known as Dynamically Controlled - Low Stress No Distortion (DC-LSND) Welding on DH-36 steel. Thermal profiles are obtained and distortion measurements are also achieved. Results show that the application of a localised cryogenic cooling source trailing the welding arc can significantly reduce weld induced distortion using the GMAW process. The effect of forced cooling on the weld microstructure is also observed.
Research To Establish A Systematic Approach To Safe Welding Procedure Development Using Austenitic Filler Material For Fabrication Of High Strength Steel, Lenka Kuzmikova, John Norrish, Huijun Li, Mark Callaghan
Research To Establish A Systematic Approach To Safe Welding Procedure Development Using Austenitic Filler Material For Fabrication Of High Strength Steel, Lenka Kuzmikova, John Norrish, Huijun Li, Mark Callaghan
Faculty of Engineering and Information Sciences - Papers: Part A
High strength, thermo-mechanically treated steels often require very careful control of welding procedures to ensure freedom from hydrogen assisted cold cracking (HACC) in the weld metal and heat affected zone (HAZ) whilst avoiding undue loss of heat affected zone strength. In practice this leads to restricted operating envelopes and the requirement for rigorous procedure management. An alternative approach is the use of austenitic welding consumables but whilst this may be expected to expand the process parameter envelope its use is often restricted by adherence to procedures previously developed for ferritic consumables. The current paper describes the research undertaken to establish …
Self-Shape Optimisation Of Cold-Formed Steel Closed Profiles Using Genetic Algorithms, Benoit Gilbert, Lip H. Teh, Hong Guan
Self-Shape Optimisation Of Cold-Formed Steel Closed Profiles Using Genetic Algorithms, Benoit Gilbert, Lip H. Teh, Hong Guan
Faculty of Engineering and Information Sciences - Papers: Part A
For economical benefits, optimisation of mass-produced structural steel products is widely researched. The objective is to minimise the quantity of material used without sacrificing the strength and practicality of the structural members. Current research focuses on optimising the dimensions of conventional cross-sectional shapes but rarely considers discovering new optimum shapes. This report introduces the concepts of a new optimisation method which enables the crosssection to self-shape to an optimum by using the evolution and adaptation benefits of Genetic Algorithm. The feasibility and accuracy of the method are verified by implementing it to find optimum thin-walled profiles against simple parameters for …
Axial Compression Tests On Frp-Jacketed Circular Concrete-Filled Thin Steel Tubes, Y M. Hu, T Yu, J G. Teng
Axial Compression Tests On Frp-Jacketed Circular Concrete-Filled Thin Steel Tubes, Y M. Hu, T Yu, J G. Teng
Faculty of Engineering and Information Sciences - Papers: Part A
Fibre-reinforced polymer (FRP) jackets have been widely used to confine concrete columns to enhance their load-carrying capacity and ductility. More recently, the use of FRP jackets to improve the performance of hollow steel tubes and concrete-filled steel tubes has also been explored. This paper presents the results of a recent experimental study in which the behaviour of FRP-confined circular concrete-filled thin steel tubes under axial compression was examined. The experimental study included three series of tests and was focussed on the effects of the diameter-to-thickness ratio of the steel tube and the confinement stiffness of the FRP jacket. The test …
Flexural Behaviour Of Hybrid Frp-Concrete-Steel Double Skin Tubular Members, T Yu, Y L. Wong, J G. Teng, S L. Dong, E S.S Lam
Flexural Behaviour Of Hybrid Frp-Concrete-Steel Double Skin Tubular Members, T Yu, Y L. Wong, J G. Teng, S L. Dong, E S.S Lam
Faculty of Engineering and Information Sciences - Papers: Part A
This paper presents the results of an experimental study on the flexural behavior of a new type of hybrid FRP-concrete-steel member as well as results from a corresponding theoretical model based on the plane section assumption and the fiber element approach. This new type of hybrid member is in the form of a double-skin tube, composed of a steel inner tube and an FRP outer tube with a concrete infill between the two tubes, and may be employed as columns or beams. The parameters examined in this study include the section configuration, the concrete strength, and the thicknesses of the …
Effect Of Aging And Deformation On The Microstructure And Properties Of Fe-Ni-Ti Maraging Steel, A Shekhter, H I. Aaronson, M K. Miller, S P. Ringer, E V. Pereloma
Effect Of Aging And Deformation On The Microstructure And Properties Of Fe-Ni-Ti Maraging Steel, A Shekhter, H I. Aaronson, M K. Miller, S P. Ringer, E V. Pereloma
Faculty of Engineering and Information Sciences - Papers: Part A
The age-hardening behavior of Fe−25.3Ni−1.7 Ti (wt pct) alloy both in undeformed specimens and in specimens cold deformed by 10 or 20 pct prior to aging was studied. The microstructural changes during aging were observed using transmission electron microscopy (TEM) and atom probe analysis and there were related to the mechanical properties as measured by microhardness and shear punch testing. An excellent combination of hardness, strength, and ductility was achieved after only 5 seconds aging at 550°C. We propose that this rapid strengthening is due to a dislocation friction effect arising from the formation of a fine dispersion of Ni−Ti …
Effect Of Deformation Schedule On The Microstructure And Mechanical Properties Of A Thermomechanically Processed C-Mn-Si Transformation-Induced Plasticity Steel, I B. Timokhina, P D. Hodgson, E V. Pereloma
Effect Of Deformation Schedule On The Microstructure And Mechanical Properties Of A Thermomechanically Processed C-Mn-Si Transformation-Induced Plasticity Steel, I B. Timokhina, P D. Hodgson, E V. Pereloma
Faculty of Engineering and Information Sciences - Papers: Part A
Thermomechanical processing simulations were performed using a hot-torsion machine, in order to develop a comprehensive understanding of the effect of severe deformation in the recrystallized and nonrecrystallized austenite regions on the microstructural evolution and mechanical properties of the 0.2 wt pct C-1.55 wt pct Mn-1.5 wt pct Si transformation-induced plasticity (TRIP) steel. The deformation schedule affected all constituents (polygonal ferrite, bainite in different morphologies, retained austenite, and martensite) of the multiphased TRIP steel microstructure. The complex relationships between the volume fraction of the retained austenite, the morphology and distribution of all phases present in the microstructure, and the mechanical properties …
Limitations Of Current Design Procedures For Steel Members In Space Frames, Lip H. Teh
Limitations Of Current Design Procedures For Steel Members In Space Frames, Lip H. Teh
Faculty of Engineering and Information Sciences - Papers: Part A
The use of more advanced methods of analysis to design steel frames may lead to substantial material savings, in addition to simplicity in the design procedures. However, these benefits do not yet appear to be a powerful incentive for many structural engineers to abandon the familiar linear elastic analysis (LEA) based design procedures, even when dealing with steel structures that are not regular rectangular frames. This paper uses a heuristic example to demonstrate the serious limitations of the LEA based design procedures, whether alignment charts or system buckling analysis is used to determine the effective lengths of the compression members. …