Search for: steel-sheet
Total 34 records
Article Materials Science and Engineering A ; Volume 447, Issue 1-2 , 2007 , Pages 174-179 ; 09215093 (ISSN) ; Akbarzadeh, A ; Daneshi, G. H ; Sharif University of Technology
In developed multiphase high strength, high formability TRIP-aided steel, Luders bands are observed similar to conventional low carbon steels. Retained austenite as the most effective constituent in TRIP steels, is responsible for Luders band formation as well as other properties such as formability, physical and mechanical properties. In the present study, a correlation between the Luders strain and the retained austenite characterization is proposed and verified by experimental evidences of the work carried out on two types of TRIP steel sheets. Intercritical annealing of cold rolled TRIP steels at different temperatures change the volume fraction of the retained austenite as well as the...
Article Materials Science and Engineering A ; Volume 528, Issue 29-30 , November , 2011 , Pages 8800-8803 ; 09215093 (ISSN) ; Kazeminezhad, M ; Sharif University of Technology
Tearing energies of annealed Al-steel bilayer sheets are investigated through multiple and single tensile tests. Total tearing energy of two layers determined separately by single tensile test is equal to tearing energy of bilayer sheet. It means that the bond between two layers has no effect on tearing energy
Article Journal of Constructional Steel Research ; Volume 122 , 2016 , Pages 292-307 ; 0143974X (ISSN) ; Alizadeh, S ; Hadidi, S ; Sharif University of Technology
Elsevier Ltd 2016
In this study six Cold-Formed Steel shear wall (CFS) with one and two side steel sheeting are tested under reversed cyclic loading. Besides, thirteen numerical models are simulated, using nonlinear finite element method, and analyzed under monotonic pushover loading. The studied parameters are the comparison of one and two side steel sheeting, the nominal thickness of steel sheet and boundary elements, and height to width aspect ratios of the wall. The performance of tested specimens is investigated in terms of lateral load-story drift response, failure modes and ultimate strength of shear walls. Based on AISI S213 the available strength of two-sided steel-sheathed walls is cumulative but...
Theoretical and Experimental Investigation of Cold Roll Welding for Production of Aluminum Clad Steel Sheet, Ph.D. Dissertation Sharif University of Technology ; Karimi Taheri, Ali
Aluminum coated steel sheet is an excellent composite material in which; the strength and economy of steel and durability of aluminum are combined. This material is produced by several methods. However, there are two main technologies to produce aluminized steel sheets: 1) the hot dip method and 2) the aluminum clad method (cold roll welding process). The hot dip method is most widely used for producing the aluminum coated steel. The aluminum coated steel sheet manufactured by this method is believed to be inferior to an aluminum sheet with respect to surface appearance, corrosion resistance and formability of the coated metal. Consequently, the aluminum clad steel method is one of the most...
Article SAE International Journal of Materials and Manufacturing ; Volume 5, Issue 1 , 2012 , Pages 60-64 ; 19463979 (ISSN) ; Ghazanfari, A ; Abrinia, K ; Assempour, A ; Sharif University of Technology
The influence of sheet thickness on sheet metal forming limits is a controversial issue; while some investigations indicate the considerable influence of thickness on forming limit diagrams (FLDs), others suggest that it is of negligible importance. In the present work, it has been demonstrated that if the thickness-reduction process is chosen so as not to alter the micro structure of the material, the forming limits do not change with variations of thickness. A material which has extensive usage in sheet metal forming processes of automotive industry (St14) has been provided. The initial thickness of the sheet is 1.5mm and using grinding process (which does not alter the microstructure) the...
Experimental Investigation of the Behavior of Squat Composite Corrugated Shear Walls Under In-Plain Shear
Sharif University of Technology
The new lateral load resisting system introduced in this dissertation is a kind of squat composite shear wall consisting of a concrete core as filler and two steel corrugated sheets as cover. Reinforced bars are not used in this kind of construction. Load resisting process of the walls is provided by 3 factors: concrete core, steel corrugated covers on both sides of the central core and shear-friction interaction between the core and covers. There is not any specific formula for their design because of their novelty and few researches on this kind of walls and absence of code provisions. In this project, squat composite walls were constructed with dimensions of 106.8×90 (cm2) from corrugated...
Article Science and Technology of Welding and Joining ; Volume 17, Issue 3 , 2012 , Pages 231-236 ; 13621718 (ISSN) ; Kokabi, A. H ; Seyed Reihani, S. M ; Sharif University of Technology
In this work, the feasibility of friction stir lap welding an aluminium alloy (Al-5083) to the aluminium clad steel sheet was studied. The welded joints were characterised by various methods including shear-tensile test and optical microscopy and scanning electron microscopy. The results indicated that sound and defect free joints were obtained. The fracture loads of the samples reached up to 94% compared with that of the steel base metal. Moreover, the joint strength linearly increased with the decrease in thickness of the aluminium layer roll bonded on the steel sheet. It was also shown that welding rotation and travel speed variation did not considerably impact the fracture loads in the...
Article Advanced Materials Research, 21 January 2011 through 23 January 2011 ; Volume 213 , January , 2011 , Pages 600-603 ; 10226680 (ISSN) ; 9783037850619 (ISBN) ; Otaaghvar, V. A ; Khaki, M. M ; Sharif University of Technology
Thermomechnical processing and controlled rolling of microalloyed steel sheets are affected by several factors according to the final properties of product. To create the high mechanical properties, a uniform and fine-grain structure is necessary in hot rolled final products. To produce such microstructures, every stage of the thermomechanical processing of the steel rolling has to be carefully controlled. Hence, first step is grain coarsening control that it usually occurs during reheating for slab. For this purpose, seven different reheating temperatures between 1000 to 1300 °C with 50 °C increments were chosen in this investigation for soaking treatment. By soaking the specimens in...
Article Journal of Materials Research and Technology ; Volume 8, Issue 3 , 2019 , Pages 3114-3125 ; 22387854 (ISSN) ; Kazeminezhad, M ; Sharif University of Technology
Elsevier Editora Ltda 2019
The application of electropulsing treatment (EPT) is studied on the microstructure and hardness of cold-rolled low carbon steel. The effects of electrical pulses on the grain refinement, precipitate size evolution and hardness are investigated. It is found that applying electrical pulse decreases the grain and precipitate size and increases the hardness in the early stages of electropulsing, but the grain and precipitate size is increased and the hardness is decreased by continuing electropulsing. Also, the effect of electropulsing treatment variables as well as treated time and number of periods are discussed. It is demonstrated that increasing treated time can accelerate achieving maximum...
Article Thin-Walled Structures ; Volume 149 , April , 2020 ; Darabi, R ; Ghabussi, A ; Habibi, M ; Foong, L. K ; Sharif University of Technology
Elsevier Ltd 2020
Tailored welded blanks (TWBs) technology can give the important possibilities to obtain components in the automobile industry. Friction stir welding (FSW) is a joining approach, which can adhere parts well with desired properties in weld zone. In this article, the main aim is investigation the effect of weld zone orientation on forming limit diagram (FLD) of the TWBs using experimental and finite element model. Three TWBs are produced FSW with three different orientations of weld zones including 00, 450 and 900 against major stress direction. The microstructure of the weld zones is divided and then observed via metallography procedures. Tensile tests are carried out to determine the...
The modeling and process analysis of resistance spot welding on galvanized steel sheets used in car body manufacturing, Article Materials and Design ; Volume 34 , February , 2012 , Pages 759-767 ; 02641275 (ISSN) ; Kolahan, F ; Kokabi, A. H ; Sharif University of Technology
In this study, the resistance spot welding (RSW) process of the galvanized interstitial free (IF) steel sheets and galvanized bake hardenable (BH) steel sheets, used in the manufacturing of car bodies, has been modeled and optimized. The quality measure of a resistance spot welding joint is estimated from the tensile-shear strength. Furthermore, four important process parameters, namely welding current (WC), welding time (WT), electrode force (EF), and holding time (HT) are considered as the factors influencing the quality of the joints. In order to develop an accurate relationship between the process inputs (4-component vectors) and the response output (tensile-shears strength) at first a...
M.Sc. Thesis Sharif University of Technology ; Movahhedi, Mojtaba
In this study, Al-5052 aluminium alloy sheet was lap joined to aluminium clad steel sheet using pulsed gas tungsten arc welding and Al-Si filler metal. Effect of heat-input, thickness of clad layer and frequency were investigated on the formation of intermetallic reaction layer, microstructure of the weld seam and shear strength of the joints are explored. Stress analysis in weld is also used in order to justify the fracture location in the welds the microstructure and shear-tensile strength of the welds (joining with A1-1050 clad layer with two thickness of 350 μm and 1000 μm). Before welding, aluminum clad steel sheets were produced by roll bonding and 450 °C annealing temperature and 90...
Differential scanning calorimetry study of constrained groove pressed low carbon steel: Recovery, recrystallisation and ferrite to austenite phase transformation, Article Materials Science and Technology (United Kingdom) ; Vol. 30, issue. 7 , 2014 , pp. 765-773 ; ISSN: 02670836 ; Kazeminezhad, M ; Sharif University of Technology
Low carbon steel sheets are subjected to severe plastic deformation (SPD) via constrained groove pressing (CGP) up to five passes. As a result of this process, strain magnitude up to 5?8 is imposed to the sheets, which leads to grain size of 225 nm. These nanostructured steel sheets, due to their high dislocation density and ultrafine microstructure, are very sensitive to heating. In the present study, recovery, recrystallisation and ferrite to austenite phase transformation phenomena for the SPD steel are investigated using differential scanning calorimetry method. The results show that with increasing the strain in steel sheets, the deformed stored energy (released through recovery and...
Resistance spot welding of ultra-fine grained steel sheets produced by constrained groove pressing: Optimization and characterization, Article Materials Characterization ; Volume 69 , 2012 , Pages 71-83 ; 10445803 (ISSN) ; Kazeminezhad, M ; Kokabi, A. H ; Sharif University of Technology
Constrained groove pressing as a severe plastic deformation method is utilized to produce ultra-fine grained low carbon steel sheets. The ultra-fine grained sheets are joined via resistance spot welding process and the characteristics of spot welds are investigated. Resistance spot welding process is optimized for welding of the sheets with different severe deformations and their results are compared with those of as-received samples. The effects of failure mode and expulsion on the performance of ultra-fine grained sheet spot welds have been investigated in the present paper and the welding current and time of resistance spot welding process according to these subjects are optimized....
Mechanical properties and microstructure of resistance spot welded severely deformed low carbon steel, Article Materials Science and Engineering A ; Volume 529, Issue 1 , 2011 , Pages 237-245 ; 09215093 (ISSN) ; Kazeminezhad, M ; Kokabi, A. H ; Sharif University of Technology
The welding of nanostructured low carbon steel sheets produced by severe plastic deformation (SPD) has been considered in the present paper. Constrained groove pressing (CGP) method is used for imposing the severe plastic deformation to the steel sheets as a large pre-strain. The SPDed sheets are joined using resistance spot welding (RSW) process. The results show that severe plastic deformation can effectively increase the electrical resistivity of steel sheets; therefore it can affect the microstructure and mechanical properties of spot welds. Microstructure and mechanical properties of fusion zone, heat affected zone (HAZ), recrystallized zone and base metal of SPDed sheets are...
Effects of cold rolling on the microstructure and mechanical properties of Fe-Ni-Mn-Mo-Ti-Cr maraging steels, Article International Journal of Minerals, Metallurgy and Materials ; Volume 18, Issue 5 , 2011 , Pages 557-561 ; 16744799 (ISSN) ; Nedjad, S. H ; Behnam, M. M. J ; Sharif University of Technology
Effects of cold rolling on the microstructure and mechanical properties of Fe-Ni-Mn-Mo-Ti-Cr maraging steels were studied. To investigate the microstructure and mechanical properties, optical microscopy, scanning electron microscopy, X-ray diffraction, tensile test, and hardness test were used. The results show that the solution-annealing treatment in the cold-rolled steel redounds to the formation of submicrocrystalline Fe2 (Mo, Ti) Laves phase particles, which are stable at high temperatures. These secondary Laves phase particles prevent from recrystallization at high temperatures and correspond to semi-brittle fracture in the subsequent aging treatment
Article Materials Science and Engineering A ; Volume 528, Issue 15 , June , 2011 , Pages 5212-5218 ; 09215093 (ISSN) ; Kazeminezhad, M ; Sharif University of Technology
However, there are many works on annealing process of SPDed non-ferrous metals, there are limit works on annealing process of SPDed low carbon steel. Therefore, in this study the annealing responses after constrained groove pressing (CGP) of low carbon steel sheets have been investigated. The sheets are subjected to severe plastic deformation at room temperature by CGP method up to three passes. Nano-structured low carbon steel sheets produced by severe plastic deformation are annealed at temperature range of 100-600 °C for 20. min. The changes of their microstructures after deformation and annealing are studied by optical microscopy. The effects of large strain and annealing temperature on...
The effect of constrained groove pressing on grain size, dislocation density and electrical resistivity of low carbon steel, Article Materials and Design ; Volume 32, Issue 6 , 2011 , Pages 3280-3286 ; 02641275 (ISSN) ; Kazeminezhad, M ; Sharif University of Technology
In this research, constrained groove pressing (CGP) technique is used for imposing severe plastic deformation (SPD) on the low carbon steel sheets. Using transmission electron microscopy (TEM), X-ray diffraction (XRD) and optical microscopy, the microstructural characteristics of produced sheets are investigated. The results show that CGP process can effectively refine the coarse-grained structure to an ultrafine grain range. Dislocation densities of the ultrafine grained low carbon steel sheets are quantitatively calculated and it is found that the CGP can effectively enhance the dislocation density of the sheets. Measurements of their electrical resistivity values show that microstructure...
Investigation on the bond strength of Al-1100/St-12 roll bonded sheets, optimization and characterization, Article Materials and Design ; Volume 32, Issue 6 , 2011 , Pages 3143-3149 ; 02641275 (ISSN) ; Kokabi, A. H ; Seyed Reihani, S. M ; Sharif University of Technology
Al-1100/St-12 aluminum clad steel sheets were produced using roll bonding process at different reductions in thickness and with various supplemental annealing treatments. Experiments were conducted by applying the Taguchi method to obtain optimum condition for maximizing the joint strength. The joint strengths of the bi-layer sheets were evaluated by peel test. The Al/Fe intermetallic phases at the joint interface and the peeled surfaces were examined using scanning electron microscopy (SEM). Energy dispersive spectroscopy (EDS) and Vickers microhardness test were performed to characterize the intermetallic compounds. The results indicate that at the optimum condition of 0.50 reduction in...
Metallurgical characteristics and failure mode transition for dissimilar resistance spot welds between ultra-fine grained and coarse-grained low carbon steel sheets, Article Materials Science and Engineering A ; Volume 637 , 2015 , Pages 12-22 ; 09215093 (ISSN) ; Kazeminezhad, M ; Kokabi, A. H ; Sharif University of Technology
Elsevier Ltd 2015
We studied the microstructure and mechanical characteristics of spot welded specimens, fabricated from low carbon steel sheets with different microstructures. Both ultra-fine grained (UFG) steel sheet and coarse grained (CG) steel sheet were used. The refined microstructure of the UFG steel has been produced by severe plastic deformation (SPD) using the constrained groove pressing (CGP) method. The grain size of the base metals was approximately 260. nm and 30. μm in diameter, respectively, in the UFG and CG steels. Examining the microstructure of a cross section cut through the spot weld reveals a similar grain size and phase distribution in the nugget on both the sides of the initial...