Mikroskopische Untersuchung von Lochkorrosion an Plasmanitriertem austenitischem rostfreiem Stahl

UNS 31603 austenitic stainless steel was nitrided using different techniques, and pitting corrosion resistance was analysed in a chloride solution. All nitriding techniques, LEII, PI· and convectional DC nitriding produced a nitrided layer called S phase which is corrosion resistant. Pits morphology and layer structure was investigated using optical and electronic microscopy, SEM-FIB, EDS, and a 3D reconstruction of a pit was assessed using FIB tomography. It was concluded that pits are initiated in MnS inclusions and a channel was generated passing through the nitrided layer, connecting the steel with the electrolyte. Base alloy dissolution was observed beneath the nitrided layer.Fil: Escalada, Lisandro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones en Ciencia y Tecnología de Materiales. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Instituto de Investigaciones en Ciencia y Tecnología de Materiales; ArgentinaFil: Brühl, Sonia Patricia. Universidad Tecnológica Nacional. Facultad Regional Concepción del Uruguay; ArgentinaFil: Simison, Silvia Noemi. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones en Ciencia y Tecnología de Materiales. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Instituto de Investigaciones en Ciencia y Tecnología de Materiales; Argentin

Mechanical and corrosion behavior of thick and soft DLC coatings

The DLC coatings are chemically inert, have low friction coefficient and good wear resistance. Depending on H content and sp3 bonds, they can be classified in “soft” or “hard” films. In this work, the corrosion and mechanical behavior, as well as the adhesion of thick DLC coatings are studied. The coatings, which are in fact silicon containing amorphous hydrogenated carbon films, were deposited by PACVD on nitrided austenitic stainless steel (duplex sample) and non-nitrided austenitic stainless steel (coated sample). The films were characterized by EDS and Raman spectroscopy, hardness was assessed by nanoindentation and microstructure was analysed by OM and SEM. To evaluate sliding wear behavior and friction, pin on disk tests were performed. The abrasive wear resistance was tested using the ASTM G65-95 Dry Sand/Rubber Wheel test. Erosion tests were conducted in water and sand flux. The corrosion resistance was evaluated by the Salt Spray Fog Test and electrochemical tests. The adhesion was tested using Scratch Test. The purpose was to systematically characterize the defects present in these thick DLC coatings relating them to adhesion, wear and corrosion resistance. The thickness of the DLC coating was about 37 μm, and its hardness was 12 GPa. The coatings presented a low friction coefficient, about 0.09. In the abrasive tests, the mass loss was negligible and in erosion experiments, the mass loss was reduced to 30%. Regarding the corrosion performance, the behavior in the Salt Spray Fog Test was good only in the duplex samples. In potentiostatic tests in 3.5% NaCl using steps, the current density increased at higher potentials for the duplex sample. Concerning the film adhesion, the critical load was also higher in theses samples than in the coated ones. The nitrided layer was a good interface for reducing the stresses and improving the adhesion, which is relevant for the decrease of the propagation rate of corrosion, when traversing defects are formed in the coating.Fil: Dalibón, Eugenia. Universidad Tecnológica Nacional. Facultad Regional Concepción del Uruguay; ArgentinaFil: Escalada, Lisandro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones en Ciencia y Tecnología de Materiales. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Instituto de Investigaciones en Ciencia y Tecnología de Materiales; ArgentinaFil: Simison, Silvia Noemi. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones en Ciencia y Tecnología de Materiales. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Instituto de Investigaciones en Ciencia y Tecnología de Materiales; ArgentinaFil: Forsich, Christian. Upper Austria University of Applied Sciences; AustraliaFil: Heim, Daniel. Upper Austria University Of Applied Sciences; AustraliaFil: Brühl, Sonia. Universidad Tecnológica Nacional. Facultad Regional Concepción del Uruguay; Argentin

Mechanical and corrosion behavior of thick and soft DLC coatings

The DLC coatings are chemically inert, have low friction coefficient and good wear resistance. Depending on H content and sp3 bonds, they can be classified in “soft” or “hard” films. In this work, the corrosion and mechanical behavior, as well as the adhesion of thick DLC coatings are studied. The coatings, which are in fact silicon containing amorphous hydrogenated carbon films, were deposited by PACVD on nitrided austenitic stainless steel (duplex sample) and non-nitrided austenitic stainless steel (coated sample). The films were characterized by EDS and Raman spectroscopy, hardness was assessed by nanoindentation and microstructure was analysed by OM and SEM. To evaluate sliding wear behavior and friction, pin on disk tests were performed. The abrasive wear resistance was tested using the ASTM G65-95 Dry Sand/Rubber Wheel test. Erosion tests were conducted in water and sand flux. The corrosion resistance was evaluated by the Salt Spray Fog Test and electrochemical tests. The adhesion was tested using Scratch Test. The purpose was to systematically characterize the defects present in these thick DLC coatings relating them to adhesion, wear and corrosion resistance. The thickness of the DLC coating was about 37 μm, and its hardness was 12 GPa. The coatings presented a low friction coefficient, about 0.09. In the abrasive tests, the mass loss was negligible and in erosion experiments, the mass loss was reduced to 30%. Regarding the corrosion performance, the behavior in the Salt Spray Fog Test was good only in the duplex samples. In potentiostatic tests in 3.5% NaCl using steps, the current density increased at higher potentials for the duplex sample. Concerning the film adhesion, the critical load was also higher in theses samples than in the coated ones. The nitrided layer was a good interface for reducing the stresses and improving the adhesion, which is relevant for the decrease of the propagation rate of corrosion, when traversing defects are formed in the coating.Fil: Dalibón, Eugenia. Universidad Tecnológica Nacional. Facultad Regional Concepción del Uruguay; ArgentinaFil: Escalada, Lisandro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones en Ciencia y Tecnología de Materiales. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Instituto de Investigaciones en Ciencia y Tecnología de Materiales; ArgentinaFil: Simison, Silvia Noemi. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones en Ciencia y Tecnología de Materiales. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Instituto de Investigaciones en Ciencia y Tecnología de Materiales; ArgentinaFil: Forsich, Christian. Upper Austria University of Applied Sciences; AustraliaFil: Heim, Daniel. Upper Austria University Of Applied Sciences; AustraliaFil: Brühl, Sonia. Universidad Tecnológica Nacional. Facultad Regional Concepción del Uruguay; Argentin

Corrosion properties of stainless steel 316 L after energetic nitrogen insertion

Using a pulse low energy ion implantation with an electronic beam switch operating in the kHz regime, a more efficient nitriding process is possible than with either pulsed plasma immersion ion implantation (PIII) or continuous low energy ion implantation (LEII). Using such an experimental setup, it is shown that the pulse length modulation (PLM) itself produces a slight beneficial effect on the corrosion behaviour of austenitic stainless steel 316 L at 400 °C. However, differences in the diffusion and phase formation exist. For 5% PLM, a lower nitrogen flux resulted in the formation of expanded austenite with a very low lattice expansion, while the highest PLM (40%) led to a reduced layer thickness caused by higher sputtering induced by the increased ion bombardment itself. Nitriding at 400 °C increases the corrosion resistance of 316 L stainless steel for all PLM. The effect is more pronounced for 15 and 30% PLM.Fil: Escalada, Lisandro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones en Ciencia y Tecnología de Materiales. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Instituto de Investigaciones en Ciencia y Tecnología de Materiales; ArgentinaFil: Lutz, Johanna. Leibniz-Institut für Oberflächenmodifizierung; AlemaniaFil: Mändl, Stephen. Leibniz-Institut für Oberflächenmodifizierung; AlemaniaFil: Manova, Darina. Leibniz-Institut für Oberflächenmodifizierung; AlemaniaFil: Newmann, H.. Leibniz-Institut für Oberflächenmodifizierung; AlemaniaFil: Simison, Silvia Noemi. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones en Ciencia y Tecnología de Materiales. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Instituto de Investigaciones en Ciencia y Tecnología de Materiales; Argentin

Hard DLC coating deposited over nitrided martensitic stainless steel:analysis of adhesion and corrosion resistance

Surface modification treatments, such as the plasma nitriding improve the tribological properties of AISI 420 stainless steel; however, the corrosion resistance is deteriorated. The DLC (Diamond-Like Carbon) coatings were not only having a low friction coefficient but also good wear and corrosion resistance. In this work, both the corrosion behavior and the adhesion of the DLC hard coating, deposited on nitrided and non-nitrided AISI 420 stainless steel substrates, were studied. The coatings were characterized by means of EDS and Raman. In addition, nitrided layer microstructure and the coatings were analyzed by SEM-FIB and XRD. Corrosion behavior was evaluated by the salt spray fog test and cyclic potentiodynamic polarization tests in NaCl solution. The adhesion wasassessed using Rockwell indentation and scratch tests. The a-C:H film and nitrided layer thicknesses were about 2.5 lm and 11 lm respectively. The nitrided layer improved adhesion in both tests. The coated AISI 420 stainless steel proved to have excellent atmospheric corrosion resistance and a passive behavior over 1 V (versus SCE) in the electrochemical tests. The adhesion and the corrosion performance were improved when the coating was deposited after the plasma nitriding treatment.Fil: Dalibon, Eugenia L.. Universidad Tecnológica Nacional. Facultad Regional Concepción del Uruguay; ArgentinaFil: Brühl, Sonia Patricia. Universidad Tecnológica Nacional. Facultad Regional Concepción del Uruguay; ArgentinaFil: Trava Airoldi, Vladimir J.. Centro de Previsao de Tempo e Estudos Climáticos. Instituto Nacional de Pesquisas Espaciais; BrasilFil: Escalada, Lisandro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones en Ciencia y Tecnología de Materiales. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Instituto de Investigaciones en Ciencia y Tecnología de Materiales; ArgentinaFil: Simison, Silvia Noemi. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones en Ciencia y Tecnología de Materiales. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Instituto de Investigaciones en Ciencia y Tecnología de Materiales; Argentin

Influence of Inclusions in the Corrosion Behavior of Plasma Nitrided Stainless Steel

Plasma nitriding is a well-established technique to improve hardness and tribological properties of austenitic stainless steel. It is proved that it is also possible to preserve the corrosion resistance after nitriding by controlling the process parameters such as time and temperature, obtaining the so-called S phase. Herein, the corrosion behavior is evaluated for nitrided layers produced by three different plasma treatments: DC plasma nitriding, plasma immersion ion implantation (PIII), and low-energy ion implantation (LEII), using different parameters in order to obtain the S-phase in thickness from 1.2 to about 6 μm without nitride precipitation. The microstructure and chemical composition of the nitrided layers is characterized by means of X-ray diffraction, secondary-ion mass spectroscopy, and scanning electron microscopy–focused ion beam. The corrosion behavior is evaluated by means of the cyclic polarization tests in NaCl solution. The morphology of the corrosion attack is studied by optical microscopy and SEM-FIB, revealing a change from crevice to pitting after the nitriding process. The inclusions are observed to be corrosion initiation sites. Due to this, the thickest nitrided layers (with high N concentration) show better corrosion behavior than the thinner ones.Fil: Escalada, Lisandro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones en Ciencia y Tecnología de Materiales. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Instituto de Investigaciones en Ciencia y Tecnología de Materiales; ArgentinaFil: Dalibon Bahler, Eugenia Laura. Universidad Tecnológica Nacional. Facultad Regional Concepción del Uruguay; ArgentinaFil: Brühl, Sonia Patricia. Universidad Tecnológica Nacional. Facultad Regional Concepción del Uruguay; ArgentinaFil: Manova, Darina. Leibniz Institute of Surface Engineering ; AlemaniaFil: Mändl, Stephan. Leibniz Institute of Surface Engineering; AlemaniaFil: Simison, Silvia Noemi. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones en Ciencia y Tecnología de Materiales. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Instituto de Investigaciones en Ciencia y Tecnología de Materiales; Argentin

Corrosion behaviour of a SiOxNy coated and nitrided PH stainless steel

Precipitation hardening stainless steels are used in applications where wear and corrosion resistance are required. To improve thesurface properties, thermochemical treatments in combination with hard coatings can be used.In this work, the corrosion behaviour of SiOxNy coatings deposited on nitrided and non-nitrided Corrax® PH stainless steel wereevaluated comparing them with the behaviour of samples which were only nitrided (two different conditions of nitrogenpercentage in the working gases were used).The microstructure was analyzed. Corrosion behaviour was evaluated by the Salt Spray Fog Test and cyclic potentiodynamicpolarization in NaCl solution. Erosion-corrosion tests were conducted.The thickness of the coating was about 1.4 microns, and its hardness was 2300 HV. The film had better erosion and corrosionbehaviour when it was deposited on the nitrided steel. This fact demonstrated that the nitrided layer results in a good interfacethat improves the adhesion and mechanical supportFil: Dalibon, Eugenia L.. Universidad Nacional de San Martin. Instituto Sabato; Argentina. Universidad Tecnologica Nacional. Facultad Regional Concepcion del Uruguay; ArgentinaFil: Moscatelli, Mauro. Universidad Tecnologica Nacional. Facultad Regional Concepcion del Uruguay; ArgentinaFil: Simison, Silvia Noemi. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Mar del Plata; Argentina. Universidad Nacional de Mar del Plata. Facultad de Ingenieria; ArgentinaFil: Escalada, Lisandro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Mar del Plata. Instituto de Investigación En Ciencia y Tecnología de Materiales (i); Argentina. Universidad Nacional de Mar del Plata. Facultad de Ingenieria; ArgentinaFil: Cabo, Amado. IONAR S.A.;Fil: Lasorsa, Carlos Alberto. Universidad Tecnologica Nacional. Facultad Regional Haedo; ArgentinaFil: Brühl, Sonia P.. Universidad Tecnologica Nacional. Facultad Regional Concepcion del Uruguay; Argentin

Cyclic contact fatigue of cemented carbides under dry and wet conditions: Correlation between microstructure, damage and electrochemical behavior

The correlation between the damage induced under cyclic contact fatigue and their electrochemical behavior (anodic polarization curves) for different WC-Co-based cemented carbides grades was investigated at the macrometric and micrometric length scale. Under both, dry (i.e. air atmosphere) and wet (cutting lubricant fluid) conditions, the crack path propagates near the carbide/metallic binder interface, resulting in tortuous cracks of several micrometers. Despite the alkaline conditions imposed by the cutting fluid (pH 9.2), the cobalt binder is preferentially dissolved, and the carbide-skeleton keeps stable. The presence of cutting fluid in the contact fatigue zone changes the morphology of the cracks due to the partial dissolution of the binder phase. The addition of chromium to the WC-Co composition enhances corrosion resistance of the metallic binder phase resulting in reduced damage of the cemented carbides in environmental assisted cyclic contact fatigue conditions.Fil: Roa, J.J.. Universidad Politécnica de Catalunya; EspañaFil: Simison, Silvia Noemi. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones en Ciencia y Tecnología de Materiales. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Instituto de Investigaciones en Ciencia y Tecnología de Materiales; ArgentinaFil: Grasso, J.. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones en Ciencia y Tecnología de Materiales. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Instituto de Investigaciones en Ciencia y Tecnología de Materiales; ArgentinaFil: Arcidiacono, M.. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones en Ciencia y Tecnología de Materiales. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Instituto de Investigaciones en Ciencia y Tecnología de Materiales; ArgentinaFil: Escalada, Lisandro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones en Ciencia y Tecnología de Materiales. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Instituto de Investigaciones en Ciencia y Tecnología de Materiales; ArgentinaFil: Soldera, F.. Universitat Saarland; AlemaniaFil: García, J.. No especifíca;Fil: Sosa, Amadeo Daniel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones en Ciencia y Tecnología de Materiales. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Instituto de Investigaciones en Ciencia y Tecnología de Materiales; Argentin

Microstructure and corrosion behavior of AISI 316L duplex treated by means of ion nitriding and plasma based ion implantation and deposition

Austenitic stainless steels are the preferred materials for mechanical components in the food, oil and chemical industries due to their good corrosion resistance but they often suffer severe wear due to their poor tribological properties. Plasma surface engineering has been extended to stainless steel hardening, through the modification of the surface with ion nitriding or the application of hard coatings. In this work, AISI 316L samples were coated with titanium nitride by means of a cathodic arc (CA) and this technique was combined with plasma immersion ion implantation, in a process called plasma based ion implantation and deposition (PBII&D). The effect on corrosion resistance was analyzed, also considering ion nitriding as a pre-treatment. Microstructure and composition were analyzed by means of glancing angle XRD, SIMS, SEM, SEM-FIB and EDS. Localized corrosion resistance was analyzed in a cyclic potentiodynamic polarization experiment in 3.5% NaCl solution, and the corroded surface was analyzed with AFM, SEM and EDS as well. It was found that nitriding at 400 °C produces a thin nitrided layer with good corrosion resistance. A duplex TiN coating resulted in a further improvement of the corrosion resistance. Comparing cathodic arc and PBII&D coating techniques, the last one gives the thickest film and also the best corrosion behavior with good adhesion.Fil: Escalada, Lisandro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Mar del Plata. Instituto de Investigación En Ciencia y Tecnología de Materiales (i); Argentina. Universidad Nacional de Mar del Plata. Facultad de Ingeniería; ArgentinaFil: Lutz, J.. Leibniz Institute of Surface Modification; AlemaniaFil: Brühl, S.P.. Universidad Tecnologica Nacional. Facultad Regional Concepcion del Uruguay; ArgentinaFil: Fazio, Mariana Andrea. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinacion Administrativa Ciudad Universitaria. Instituto de Física del Plasma; ArgentinaFil: Marquez, Adriana Beatriz. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinacion Administrativa Ciudad Universitaria. Instituto de Física del Plasma; ArgentinaFil: Mändl, S.. Leibniz Institute of Surface Modification; AlemaniaFil: Manova, D.. Leibniz Institute of Surface Modification; AlemaniaFil: Simison, Silvia Noemi. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Mar del Plata. Instituto de Investigación En Ciencia y Tecnología de Materiales (i); Argentina. Universidad Nacional de Mar del Plata. Facultad de Ingeniería; Argentin

Contact fatigue behavior of a-Al2O3-Ti(C,N) CVD coated WC-Co under dry and wet conditions

The response to cycling contact fatigue load of a WC-6%Co carbide coated with a Ti(C,N)/a-Al2O3 CVD multilayer was investigated in dry and wet conditions. Imprints in dry conditions were characterized by small thin cracks forming a circumference at the maximum radii of the imprint. The damaged coating was totally present in the final imprint of the dry test. Wet indentations showcase an area in the imprint where the a-Al2O3 layer has been removed throughout a ring but was kept at the center of the indentation, suggesting that the coating damage under cycling contact load in wet conditions is dominated by a-Al2O3 degradation, associated with a fretting effect or tangential loads accelerating the fatigue-corrosion of the alumina layer.Peer ReviewedPostprint (author's final draft