Search results for "Steel"
showing 10 items of 338 documents
Parametric study of laser welding of copper to austenitic stainless steel
2018
Abstract Welding of copper to stainless steel is challenging because of sharp difference in thermophysical properties of materials and the presence of miscibility gap in Fe-Cu system. The parametric study of continuous Yb:YAG laser welding between copper and austenitic stainless steel 316L has been performed. The influence of laser power, welding speed and beam offset from joint line on weld composition, microstructure and tensile properties was studied. The corrosion behaviour of the welds was evaluated in 0.1M NaCl with the potentiostatic pulse testing method, salt fog and immersion tests. In function of copper dilution in the melted zone, different types of microstructure were observed: …
Fibrous reinforced concrete beams in flexure: Experimental investigation, analytical modelling and design considerations
2008
Abstract The flexural behavior of plain and fibrous reinforced concrete (FRC) beams under monotonic and cyclic actions was analysed. Twelve beams were reinforced with top and bottom longitudinal deformed steel bars and transverse steel stirrups. Concrete, having 30 MPa cylindrical strength, was reinforced with hooked steel fibres at a volume percentage of 1%. Beams, 600 mm in length and with a square side cross-section of 150 mm, were tested in flexure using a three point bending test, adopting three different cover thicknesses of 5, 15 and 25 mm, respectively. The results obtained show that the addition of fibers increases the bearing capacity of the beams and ensures more ductile behaviou…
Flexural behaviour of concrete corbels containing steel fibers or wrapped with FRP sheets
2005
In the present paper an analytical and experimental investigation referring to the flexural behaviour of reinforced concrete corbels subjected to vertical forces is presented. For fixed shape and dimensions of the corbels the experimental investigation analyses the effects of the following: longitudinal and transverse steel reinforcements; fiber reinforced concrete (FRC) with hooked steel fibers; external wrapping retrofitting technique with a thin layer of carbon fiber sheet (CFRP). The analytical model based on equivalent truss structures, allows one to determine the bearing capacity of corbels, distinguishing the different ultimate states reached. The analytical results are then compared…
Structural Behavior of Telescopic Steel Pipe for a Full-Scale 60 kW Wind Turbine Tower
2020
A simple analytical model, including local effects due to buckling and shear to moment interaction, was developed to pre-dict the load-carrying capacity of CHS tubes under flexure and shear. A finite-element analysis with ABAQUS Code was also conducted for validation of the proposed model. By properly modeling the imperfection effects due to the ovalization of steel tube, a good correlation of the structural response and failure mode was also achieved, and a good correlation with the analytical model was also achieved. Numerical and analytical results were compared with experimental results recently obtained by the author with good agreement. Experimental tests refer to full-scale static te…
Mechanical and cohesion properties of brass plated steel cords in a sulphurizing environment
1986
The mechanical and cohesion properties of brass plated steel cords have been investigated in dry hydrogen sulphide between 25 and 450° C. The extents of elastic and plastic regions, obtained from slow strain rate technique data have been defined, and the preferential site of decohesion tends to be the brass-steel interface.
Interactions in dual species biofilms between Listeria monocytogenes EGD-e and several strains of Staphylococcus aureus.
2008
International audience; Six environmental isolates of Staphylococcus aureus and one collection strain were investigated for their ability to form monospecies biofilms and dual species biofilms with Listeria monocytogenes EGD-e on stainless steel coupons. All isolates were able to grow as biofilms but their ability to form monospecies biofilms differed. The population of L. monocytogenes EGD-e in dual species biofilms was not affected by the presence of S. aureus isolates except for strain CIP 53.156. The effect of L. monocytogenes EGD-e on the population of S. aureus was strain dependent: S. aureus population either increased or decreased or was not affected in the presence of L. monocytoge…
Effects of various hygiene procedures on the surface characteristics of titanium abutments.
1996
The use of cleaning instruments on titanium implants may cause undesired surface alterations. In a qualitative and quantitative assessment of these alterations, 5 titanium implant abutments were treated with a steel curet, a prototype pure titanium curet, an air abrasive polishing system, and an ultrasonic system. Custom-made polymer templates, used to secure the curet to a vertical guide bar and a spring scale to maintain a constant instrument pressure, guaranteed a standardized procedure and reproducible results. The ultrasonic and the air abrasive polishing method were also standardized. Evaluation by scanning electron microscopy (SEM) revealed surface alterations for all instruments and…
Role of Molybdenum on the Electronic Properties of Passive Films on Stainless Steels
2020
Potentiostatic polarization of different stainless steel grades with a mirror surface finishing was performed in order to investigate the role of Mo on stainless steels corrosion behaviour. In the attempt to gain more insight into transpassive dissolution mechanism, passive films were grown in neutral aqueous solution (pH ∼ 7) at different polarizing potentials ranging from passive to transpassive conditions. According to the photoelectrochemical characterization, Cr dissolution occurs even at low polarizing potentials in the case of AISI 304L, while higher band gap values were obtained for passive films grown on austenitic 316L and duplex SSs. Capacitance measurements suggest that the flat…
Exploring corrosion protection properties of alkyd@lanthanide bis-phthalocyanine nanocomposite coatings
2017
Organic coatings have been widely used to protect carbon steel pipelines from external corrosion; however, they often suffer from permeability and weak adhesion. Here we show that synthetic lanthanide bis-phthalocyanine complexes, LnPc2 (Ln = lanthanide metal, Pc = C32H16N8 denotes the phthalocyanine ligand) can be used to form new nanocomposite coatings to provide corrosion protection to the underlying carbon steel pipelines. Electrochemical studies (EIS and potentiodynamic polarization) showed that the incorporation of LnPc2 compound (PrPc2, SmPc2 and HoPc2) additives with alkyd coating, leads to a significant increase in the corrosion resistance of carbon steel in 0.5 M HCl solution. The…
Sul controllo del meccanismo di collasso di controventi eccentrici
2007
The effectiveness of different non-linear static procedures, for the detection of the collapse mechanism of eccentric braced frames, is investigated. EBFs introduced into truss frame structures are considered. For such a typology of structures, plastic deformations are concen-trated in a single resistant element at each floor, greatly increasing the risk of the formation of soft storey mechanisms, even if the structure is designed according to the capacity design. The results of different non-linear static procedures are compared to those obtained by incremental dynamic non-linear analysis, considering a meaningful set of artificially generated stationary accelerograms, compatible with a ta…