Papers by Keyword: Low Carbon Steel

Abstract: Metal-polymer composites are advanced materials for the aerospace, automotive and railway industry where details and elements of construction are affected by impact, cyclic and vibration loads. In the present work layered composites based on steel, aluminum alloy and rubber as intermediate layers were obtained by cold and hot bonding using adhesives. Adhesive lap-shear bond strength of layered composites fabricated by various techniques was determined using tensile shear test. To evaluate the mechanical behavior of layered metal-rubber composites under simulated operational conditions static, dynamic and cyclic, three points bending tests were carried out. The results of mechanical tests of these composites indicated that hot bonding is the most preferred fabrication method for the formation of increased mechanical characteristics.

Abstract: The resistance spot welding is adopted to joint dissimilar alloys such as aluminum alloy 1100 , and low carbon steel alloy 1008 by using cover plate. This study aims to optimization the best conditions of dissimilar welding of Aluminum with low carbon steel by RSW, and improving the properties of joints by many method. three different variables were used for the welding process: welding current (5, 6 ,7 and 8 KA), weld time (0.5, 1 and 1.5 sec) and electrode force (13.2 and 15.5 N).The welding joints are ―examined by a scanning electron microscope SEM and a X-ray diffraction‖ for the purpose of discussing the causes of the improved characteristics. The results revealed that the best welding conditions were under welding current 7 KA , weld time 1 sec and electrode force 13.2 KN, where the joint possessed the maximum shear force (4.8KN) and after improvement the tensile shear force become (6.02 KN), in addition to presence of the intermetallic compounds at optimum condition , such as AlFe3,Al5Fe4 and Al13Fe4, in the joint layer between dissimilar metal improves of the tensile shear forces and hardness in fusion zone.

Abstract: In the present work, corrosion inhibition of low carbon steel in a 1M H2SO4 solution by pectin nanoparticles extract was studied by potentiostatic and weight loss methods. Increasing the acid concentration leads to an increase in the corrosion rate of the electrode. The variable conditions of the pectin nanoparticles used in this investigation are (2 to 10g/l at 25oC). It was found that the concentrates acts as a compelling consumption inhibitor for gentle steel in an acidic medium. The hindrance process is credited to the adsorbed film development of the inhibitor on the metal surface of that protects the metal against corrosion. It was observed that the efficiency of the inhibition rose with increased inhibitor concentration up to the maximum level of 92% for 10 g/l at 25 oC. The results showed that the corrosion rate without the inhibitor was 2.263mpy while with the inhibitor 0.179 mpy, meaning that the rate of corrosion improved more than 90%. The results of the immersion time (1 h) at 25oC on the inhibition of the corrosion also indicated improved corrosion resistance. The results demonstrated that an extract of pectin nanoparticles could serve as an excellent eco-friendly, green corrosion inhibitor. Fourier- transform infrared spectroscopy (FTIR) results indicate that these nanoparticles contain various chemical bonds (C-C, CH2, C-O-C, and cellulose) with metal surfaces, lead to producing a barrier layer that protects the surface.

Abstract: Asymmetric rolling with different work roll circumferential speeds is a process that can be used for improvement of mechanical properties of the processed metals and alloys. Development of the model, which allow to calculate the stress-strain state occurring in the microstructure of the ferritic-pearlitic steels during asymmetric rolling, was the main objective of this paper. Macro level models do not take into account the complicated behavior of the ferritic-pearlitic microstructure in the micro scale. Therefore, development of modelling methods, which allow predicting the properties distribution in the metal volume with the behavioral features of the microstructure under the influence of the deformation, was needed. Representative Volume Element (RVE), representing ferritic-pearlitic steel microstructure, was developed. Simulations of the asymmetric rolling process were performed and local deformation of each structural component was predicted. Selected results, as well as discussion of the effect of microstructure on obtained stress and strain distributions, are presented in the paper. Results of multiscale simulation analysis of the deformation characteristics, presented in this study, can be used for optimization of the asymmetric rolling process.

Abstract: In this research, low carbon steel surface was modified using electrophoretic deposition (EPD) technique from a graphene oxide (GO) water suspension. The electrophoretic deposition (EPD) is the technique used for manipulation and deposition of nanomaterials. The GO coating was used as a layer to increase the hardness of low carbon steel. GO was successfully synthesized using the modified Hummers method. EPD technique was performed by applying voltage at 9 volts and the deposition time of 15 mins. The working distance between the cathode and anode was fixed at 15 mm. The GO film had been deposited by EPD technique where it was carburized at 900, 950, 1000 and 1050°C, for 60 mins. The microstructure of the carbide film was investigated using scanning electron microscopy (SEM). As the carburization temperature raised (1050°C), more volume carbon atoms reacted with iron atoms to form iron carbon (Fe₃C) layer on to the substrate surface. The carbide films are columnar crystal growth with a particle size of approximately 50 μm. The growth rate of the carbide films at 1050°C is about 8 µm/min. Energy dispersive X-ray spectrometer (EDS) was studied for chemical elements analysis. Fe, C and O elements were then detected. At carburization temperature of 1050°C, it showed that C element distribution is higher than others’ temperatures. Moreover, the hardness on the carbide films was investigated using a Vickers hardness tester under an applied load of 500 grams for 10 seconds. It was found that the hardness increased with the increasing carburization temperatures. The hardness of low carbon steel is 172.99 ± 2.28 HV. After the carburization processing via GO at temperature of 1050°C, the highest hardness of 821.42 ± 35.33 HV was obtained. It was observed that the mechanical properties of low carbon steel surface were found to be strongly influenced by the process of carburization temperature.

Abstract: Normalizing is an effective heat treatment in improving the microstructure and developing the mechanical properties of micro-alloyed steel. The normalizing parameters such as temperature and holding time are the main keys to microstructure and mechanical properties controlling. Therefore, obtaining an optimum combination of mechanical properties must be subjected to an ideal combination of these parameters. Furthermore, adjusting the optimum normalizing parameters must be considered for every chemical composition depending on the critical transformation temperatures. In this work, four micro-alloyed steel alloys containing V (0.008-0.1wt %) and Ti (0.002-0.072) were held on different normalizing temperatures for 30 minutes. The first holding temperature was carried out just above the Ac3 temperature and the second was carried out above the Ac3 by 100°C (Ac3+100°C). With the controlled normalizing condition, V-Ti-micro-alloyed steel alloy has produced an ultra-fine structure of grain size 2.2 microns and combined high strength of 725 MPa YS, 1058 MPa UTS and good ductility of 20%.

Abstract: Despite that the conventional CSiMn TRIP steel has a promissing mechanical attributes, it has a limitations on the galvanizability of such grades of steel due to Silicon. Thus, aluminum as a strong candidate for substituting silicon has been introduced in this study accompanied by vanadium as a microalloying element. Microstructure of the studied steel was observed by using OM, and SEM. X-ray diffraction analysis, and tent-etching technique carried out on the studied steel to identify the fractions of the retained Austenite after thermal mechanical process, as well as its morphology. In addition, the mechanical properties in term of strength, ductility, strain hardening, and the rate of strain hardening were studied to define the influenced parameters throughout this alteration. The results refer to the possibility of complete replacement of silicon in TRIP steel with aluminum at the presence of vanadium as a micro alloying element.

Abstract: Specimens of pipe steel of increased strength grade type K56-K60, with different values of impact toughness (KCV) were investigated: a metallographic examination of the specimens’ structure was carried out by optical and electron scanning microscopy methods. The interrelation of the microstructure with mechanical properties, in particular with impact toughness and their influence on the nature of fracture pattern is established.

Abstract: This work, presents some heat treatments were used to improve the microstructure in different zones of the API X70 welded pipeline steel. In this study a shielded metal arc welding (SMAW) process has been realized.. Scanning electron microscopy and X-ray diffraction have been used as characterization techniques to observe the WM microstructures, in addition hardness are also measured. The results revealed that the isothermal heat treatment caused progressive recristallization reactions in the weld zone, and the hardness of weld joints decreased, were the main transformations after increasing the temperature of the heat treatment.

Abstract: Friction surfacing is a solid-state coating technique process in which a mechtrode is rotated against the substrate under pressure, henceforth forming a coat on the substrate. This process not only can be used as coating process but it also provides flexibility in coating different materials as a revamp manufacturing process and it is suitable for getting excellent mechanical properties after the surfaced deposits. Bond strength is very good and these deposits are expected to serve better service life. The present work deals with mechtrode of SS-316, D3-tool steel and aa-2014 are coated on low carbon steel substrate by friction surfacing process and design of experiment were done by using taguchi L9 orthogonal array where the process parameters are mechtrode, rotational speed and traverse speed. The coating thickness, coating width and the SEM-microstructure analysis were studied.