Search results for " Stainless Steel"

Passivation-Induced Physicochemical Alterations of the Native Surface Oxide Film on 316L Austenitic Stainless Steel

2019

Time of Flight Secondary Ion Mass Spectroscopy, X-Ray Photoelectron Spectroscopy, in situ Photo-Current Spectroscopy and electrochemical analysis were combined to characterize the physicochemical alterations induced by electrochemical passivation of the surface oxide film providing corrosion resistance to 316L stainless steel. The as-prepared surface is covered by a ~2 nm thick, mixed (Cr(III)-Fe(III)) and bi-layered hydroxylated oxide. The inner layer is highly enriched in Cr(III) and the outer layer less so. Molybdenum is concentrated, mostly as Mo(VI), in the outer layer. Nickel is only present at trace level. These inner and outer layers have band gap values of 3.0 and 2.6-2.7 eV, respe…

Repassivation of the damage generated by cavitation on UNS N08031 in a LiBr solution by means of electrochemical techniques and Confocal Laser Scanni…

2010

Abstract The objective of this work is to study the influence of cavitation on the corrosion behaviour of Alloy 31, a highly-alloyed austenitic stainless steel (UNS N08031), in a LiBr heavy brine solution (992 g/L) at 25 °C. The presence of cavitation shifted the OCP value towards the active direction by 708 mVAg/AgCl, increased anodic current densities and passivation current density, ip, and reduced the pitting potential, Ep. Repassivation behaviour of Alloy 31 has been investigated by using potentiostatic tests at different potentials. The current density transient obtained after interrupting cavitation was used to obtain the repassivation index, n, provided by the slope of the log i(t) …

Study of Passive Films Formed on AISI 316L Stainless Steel in Non-Polluted and Underwater-Volcano-Polluted Seawater

2014

This work studies the semiconducting behavior of passive films formed on AISI 316L (UNS S31603) in two different sea-water solutions, non-polluted and polluted, collected from the volcano of El Hierro Island. Polarization measurements, potentiostatic passivation tests, electrochemical impedance spectroscopy, and capacitance measurements were performed. Results show that the polluted seawater worsens passivation kinetics. Additionally, passive films formed on AISI 316L stainless steel in polluted seawater have been found to be less protective than those formed in non-polluted seawater, showing a more defective structure, owing to the acidity of the polluted medium.

Influence of the microstructure on the corrosion behaviour of low-carbon martensitic stainless steel after tempering treatment

2014

Abstract The microstructure of grade X4CrNiMo16.5.1 stainless steel was studied at different scales. The chemical composition of the native passive film formed on the different phases was then determined at the microscale. The degree of homogeneity of the native passive film is discussed. Subsequently, the susceptibility to pitting corrosion of X4CrNiMo16.5.1 was quantified using the electrochemical microcell technique. The nature of precursor sites and the morphology of pits were investigated by combining scanning electron microscopy with Electron BackScatter Diffraction and potentiostatic pulse tests. The role of the microstructure and the cold-worked layer generated by polishing in pitti…

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: …

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…

ODS ferritic steels obtained from gas atomized powders through the STARS processing route: Reactive synthesis as an alternative to mechanical alloying

2018

Authors acknowledge ALBA synchrotron (Spain) for the provision of beamtime on the beam line BL22-CLAESS (Proposal 2016081797). Transmission electron microscopy observations were accomplished at Centro Nacional de Microscopía Electrónica, CNME-UCM. This work has been carried out within the framework of the EUROfusion Consortium and has received funding from the Euratom research and training programme 2014–2018 under grant agreement No 633053. The views and opinions expressed herein do not necessarily reflect those of the European Commission. Financial support from Basque Government through the ELKARTEK ACTIMAT 2016 project is also acknowledged.

Numerical Modelling for Assessing the Structural Efficiency of CAM® Reinforcement System for Masonry Walls

2022

A large portion of the Italian building heritage is made of masonry construc-tions, which were erected in the first decades of the last century and were conceived to support gravitational loads only. Many research activities have been carried out in order to propose retrofitting techniques aimed at improving seismic behaviour of existing ma-sonry buildings. The present paper focuses on the CAM® reinforcing system. Such a retrofitting technique, which is widely used in Italy, consists in the application of pre-tensioned stainless steel ribbons on existing masonry walls, conferring to them addi-tional strength, ductility and beneficial confinement effects. The preliminary outcomes of a common…

Physico-chemical characterization of passive films on 316L stainless steel grown in high temperature water

2014

Toward more realistic viscosity measurements of tyre rubber–bitumen blends

2014

AbstractThe measurement of rheological properties of the tyre rubber bitumen blends is often challenging due to presence of suspended tyre rubber’s crumbs. Furthermore, the phase separation during the course of measurements makes the viscosity of these non-homogeneous blends difficult to ascertain. In this study, a new dual helical impeller was designed and manufactured to be used with a rotational viscometer in order to have a real-time control of the viscosity while performing a laboratory mixing of the blends. Layer based manufacturing techniques showed to be a convenient method to produce complex shaped impeller prototypes before manufacturing the more expensive stainless steel assembly…