TY - CONF A1 - Rosemann, Paul A1 - Reinemann, Steffi A1 - Lehmann, Jens A1 - Babutzka, Martin A1 - Burkert, Andreas T1 - Einfluss industrieller Korundschleifprozesse auf die Korrosionsbeständigkeit nichtrostender Stähle N2 - Im Vortrag werden Ergebnisse des AiF Forschungsvorhabens "Optimierung industrieller Korundschleifprozesse zur Sicherstellung der Korrosionsbeständigkeit nichtrostender Stähle" vorgestellt, die den Einfluss verschiedener Schleifmittel auf die Korrosionsbeständigkeit geschliffener Oberflächen nichtrostender Stähle belegen. Es konnte ein signifikanter Einfluss durch die Verwendung von Granulatschleifbändern nachgewiesen werden, der die Korrosionsbeständigkeit der Oberflächen reduziert. Grund sind auf der Oberfläche zurückbleibende Materialaufplattungen von Eigenmaterial aus dem Schleifprozess. Es wurden unterschiedliche Korrosionsuntersuchungen durchgeführt und durch Oberflächenanalytik im Rasterelektronenmikroskop untermauert. T2 - Sitzung des Arbeitskreises "Korrosion und Korrosionsschutz" von Eisen und Stahl" der Gesellschaft für Korrosionsschutz e.V. CY - Duisburg, Germany DA - 12.12.2018 KW - Korrosion KW - Korrosionsschutz KW - Schleifen KW - Oberfläche KW - Nichtrostender Stahl KW - KorroPad KW - Oberflächenanalytik KW - Lochkorrosion KW - Korrosionsbeständigkeit PY - 2018 AN - OPUS4-47034 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Rosemann, Paul A1 - Babutzka, Martin T1 - Vorstellung des Programms WIPANO sowie aktueller Projektskizzen der BAM im Fachbereich 7.6 N2 - Der Vortrag erläutert die Förderschwerpunkte der Förderinitiative WIPANO des BMWi und zeigt aktuelle Projektskizzen sowie Projekte des Fachbereiches 7.6. T2 - Sitzung des Arbeitskreises "Korrosion und Korrosionsschutz von Eisen und Stahl" der Gesellschaft für Korrosionsschutz e.V. CY - Duisburg, Germany DA - 12.12.2018 KW - Korrosion KW - Korrosionsschutz KW - WIPANO KW - Norm KW - KorroPad KW - Gelartige Elektrolyte KW - Betonstahl KW - Zinkdeckschichten PY - 2018 AN - OPUS4-47035 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Rosemann, Paul A1 - Müller, C. A1 - Baumann, O. A1 - Halle, T. T1 - Einfluss der Schweißnaht-Nachbehandlung auf die Korrosionsbeständigkeit des Duplex-Stahls 1.4062 N2 - Die Korrosionsbeständigkeit von Schweißverbindungen aus dem Duplex-Stahl 1.4062 wird, neben dem Grundwerkstoff, dem Schweißzusatzwerkstoff und dem Schweißverfahren, auch sehr stark von der Oberflächennachbehandlung der Schweißnaht beeinflusst. Je nach zukünftigem Anwendungsbereich und geforderter Korrosionsbeständigkeit wird die Schweißnaht geschliffen, gebeizt, elektropoliert oder gestrahlt, um die beim Schweißen entstandenen Anlauffarben zu entfernen. Gestrahlte Oberfläche sind in der industriellen Praxis häufig anzutreffen, da sie deutlich einfacher und kostengünstiger herzustellen sind als gebeizte oder elektropolierte Oberflächen. Die Auswahl des Strahlmittels bestimmt auch die Prozesskosten, wobei das Strahlen mit Korund effektiver als das Strahlen mit Glasperlen ist. Ziel der Untersuchungen war es festzustellen, ob das Strahlen aus Sicht der Korrosionsbeständigkeit äquivalent zu anderen Nachbehandlungsverfahren ist. Diese Fragestellung wird im Vortrag beantwortet indem geschliffene, gebeizte, mit Korund gestrahlte und mit Glasperlen gestrahlte Schweißverbindungen vergleichend untersucht werden. Die Ergebnisse der Untersuchungen von den Strahlmitteln und den gestrahlten Oberflächen werden mit den Ergebnissen der Salzsprühnebelprüfung, den kritischen Lochkorrosionspotentialen und der KorroPad-Prüfung korreliert. T2 - Sitzung des Arbeitskreises "Korrosion und Korrosionsschutz von Eisen und Stahl" der Gesellschaft für Korrosionsschutz e.V. CY - Duisburg, Germany DA - 12.12.2018 KW - Korrosion KW - Korosionsschutz KW - Duplexstahl KW - KorroPad KW - Nichtrostender Stahl KW - Lochkorrosion KW - Schweißen KW - Oberflächen KW - Strahlen PY - 2018 AN - OPUS4-47036 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Rosemann, Paul A1 - Kauss, N. A1 - Müller, C. A1 - Halle, T. T1 - Heat treatment and corrosion resistance of cutlery N2 - Hardness and pitting corrosion resistance are the major quality criteria of cutlery. Both are achieved by the heat treatment (austenitization, quenching and tempering) of the normally used martensitic stainless steels. The established quality control method regarding the pitting corrosion resistance is an alternating immersion test in 1 % NaCl solution at 60 °C according to DIN EN ISO 8442. This standard test shows a high deviation, which limits any optimization of the heat treatment process. New approaches for corrosion testing of martensitic stainless-steels were developed and used in the last years to connect the weak pitting corrosion resistance of martensitic stainless-steels with the phenomenon of chromium depletion. The tempering temperatures used in the industrial heat treatment of cutlery are too low to explain the appearance of chromium depletion. For this reason, a systematic investigation of three heat treatment parameters (austenitization time, cooling speed and tempering temperature) were performed on the martensitic stainless-steels X50CrMoV15 (1.4116) to detect their contribution to chromium depletion. The electrochemical potentiodynamic reactivation (EPR), which is very sensitive to any change of the microstructure, was used to quantify the degree of chromium depletion. The KorroPad indicator-test was applied to correlate low pitting corrosion resistance to the presence of chromium depletion. The results of all investigations allow conclusions about the very small process window, which is necessary to achieve cutlery with high pitting corrosion resistance. T2 - EUROCORR 2018 CY - Krakow, Poland DA - 09.09.2018 KW - Corrosion KW - KorroPad KW - Stainless steel KW - Corrosion resistance KW - Heat treatment KW - EPR KW - Pitting corrosion KW - Martensitic stainless steels KW - REM PY - 2018 AN - OPUS4-45952 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Rosemann, Paul A1 - Kauss, N. T1 - Visualization of material-related susceptibility to pitting corrosion with the “KorroPad” indicator test N2 - The KorroPad indicator test was invented at the Federal Institute for Materials Research and Testing to detect stainless-steel surfaces susceptible to pitting corrosion. The KorroPad indicator test is thus an interesting alternative for manufacturers, processors, users and researchers to time consuming exposition experiments and complex electrochemical investigations, which are normally used to reveal surface-related processing errors resulting in reduced pitting corrosion resistance. Furthermore, the KorroPad indicator test can be used to visualize alloy- and microstructure-related factors causing susceptibility to pitting corrosion. The detection limit of the KorroPad indicator test was characterized in this work using reference alloys with different chromium content (5 % to 18 %). The alloy-specific detection limit was shifted successfully to higher chromium content by increasing the concentrations of NaCl and K3[Fe(CN)6]. The modified KorroPads can now be used to establish an alloy-specific quality control regarding the pitting corrosion resistance of different stainless steel grades. T2 - EUROCORR CY - Krakow, Poland DA - 09.09.2018 KW - Corrosion KW - KorroPad KW - Stainless steel KW - Corrosion resistance KW - Corrosion testing KW - Pitting corrosion PY - 2018 AN - OPUS4-45953 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Rosemann, Paul A1 - Müller, C. A1 - Roßberg, S. A1 - Pensel, P. A1 - Halle, T. A1 - Burkert, A. T1 - Precipitation behavior and corrosion resistance of nickel-free, high-nitrogen austenitic stainless steels N2 - Nickel-free, nitrogen alloyed austenitic stainless-steels, with about 19 wt.-% Mn and 0,8 wt. % N, are an interesting alternative to classic CrNi austenitic stainless steels due to their superior mechanical properties (Rm > 900 MPa, A5 > 50 %, Av > 350 J) in the solution annealed condition. The formation of chromium-rich nitrides during suboptimal heat treatment, processing or application leads to an inhomogeneous distribution of alloying elements in the microstructure, which reduces the corrosion resistance. Consequently, an accurate knowledge of the sensitization behavior is indispensable for the use of nickel-free, high-nitrogen austenitic stainless steels. The relationship between artificial aging, phase formation and corrosion resistance was investigated on the alloys X8CrMnN18-19 (1.3815) and X8CrMnMoN18-19-2 (1.4456), both alloyed with 0,8 wt.-% Nitrogen, in the present work. The microstructural evolution was studied by LM and SEM while the corrosion resistance was characterized with the electrochemical potentiodynamic reactivation (EPR) and the KorroPad indicator-test. Both alloys showed increased corrosion susceptibility within critical aging parameters. Finally, a sensitization diagram was described successfully for both alloys showing the positive effect of molybdenum. T2 - EUROCORR 2018 CY - Krakow, Poland DA - 09.09.2018 KW - Corrosion KW - KorroPad KW - Stainless steel KW - Corrosion resistance KW - Heat treatment KW - ThermoCalc KW - Pitting corrosion KW - Nitrogen PY - 2018 AN - OPUS4-45954 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kauss, N. A1 - Rosemann, Paul A1 - Halle, T. T1 - Age-hardening behaviour, microstructure and corrosion resistance of the copper alloyed stainless steel 1.4542 N2 - The copper alloyed stainless steel 1.4542 (X5CrNiCuNb16-4) is used in different areas due to its good mechanical properties and corrosion resistance. Strength and corrosion re-sistance can be adjusted by the heat treatment, which is of importance for the application of this alloy. The mechanical properties (strength and hardness) are attributed to the dispersive precipitation of the copper rich ε–Phase. The additional precipitation of chromium carbides can reduce the corrosion resistance. Different ageing states were produced to investigate the precipitation behaviour with various methods. Furthermore, the influence of cold-rolling on the precipitation behaviour was studied in comparison to a solution annealed state without deformation. The microstructure was studied by SEM and the variations of hardness and magnetic proportion were characterised. The electrochemical potentiodynamic reactivation (EPR) was used to determine the corrosion resistance and detect chromium depletion in all heat-treated states. The results show that a work hardening accelerates the precipitation rate, while ageing at 600 °C reduces the corrosion re-sistance due to chromium depletion. T2 - EUROCORR 2018 CY - Krakow, Poland DA - 09.09.2018 KW - Corrosion KW - Stainless steel KW - Corrosion resistance KW - EPR KW - Corrosion testing KW - Heat treatment KW - ThermoCalc KW - REM KW - Martensitic stainless steels PY - 2018 AN - OPUS4-45955 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Rosemann, Paul A1 - Lehmann, Jens A1 - Burkert, Andreas T1 - Corrosion resistance of ferritic stainless steels studied with various methods on different time scales N2 - The corrosion resistance of stainless-steels grades is of high importance for the technical safety in different environmental conditions. Processing and surface finish influences the corrosion resistance of ferritic stainless steels, which may be considered for some application in marine environment. Three ferritic stainless steel alloys (X2CrNi12, X2CrTiNb18 and X2CrMoTi18-2) were exposed in four different surface finishes (rolled, dry grinding, glass beaded and electro polished) for five years in marine environment to obtain reliable information about the corrosion resistance. All samples were assessed after 22 and 60 months according to DIN EN ISO 10289 in validation degrees from 1 to 10. Complementary investigation using accelerated chamber test (salt spray test followed by four weeks storage at 30 °C / 80 % relative humidity) and short-term electrochemical methods (electrochemical potentiodynamic reactivation, pitting potentials and the KorroPad method) were conducted to compare their results. The presentation gives an overview on all methods and the generated results, which show benefits and restrictions of long-term, accelerated and short-term corrosion tests. T2 - EUROCORR 2018 CY - Krakow, Poland DA - 09.09.2018 KW - Corrosion KW - Stainless steel KW - Corrosion resistance KW - EPR KW - Corrosion testing KW - Pitting corrosion KW - Atmospheric corrosion KW - Surface treatment PY - 2018 AN - OPUS4-45940 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Rosemann, Paul A1 - Baumann, O. A1 - Müller, C. T1 - Influence of the post-weld surface treatment on the corrosion resistance of the duplex stainless steel 1.4062 N2 - The duplex stainless steel 1.4062 (X2CrNiN22-2) is used as alternative material to austenitic stainless steels in the construction industry. The corrosion resistance of welded seams is influenced by the base material, the weld filler material, the welding process and also by the final surface treatment. The scale layer next to the weld seam can be removed by grinding, pickling, electro-polishing or blasting depending on the requested corrosion resistance. Blasted surfaces are often used in the industrial practice due to the faster and cheaper manufacturing process compared to pickled or electro-polished surfaces. Furthermore blasting with corundum-grain is more effective than blasting with glass-beads which also lower the process costs. In recent years, stainless steel surfaces showed an unusually high susceptibility to pitting corrosion after grinding with corundum. For this reason, it is now also questioned critically whether the corrosion resistance is influenced by the applied blasting agent. This question was specifically investigated by comparing grinded, pickled, corundum-grain- and glass-bead-blasted welding seams. Results of the SEM analyses of the blasting agents and the blasted surfaces will be presented and correlated with the results of different corrosion tests (KorroPad-testing and pitting potentials). T2 - Materials Science and Engineering 2018 (MSE) CY - Darmstadt, Germany DA - 26.09.2018 KW - Duplexstahl KW - Korrosion KW - Nichtrostender Stahl KW - Schweißen KW - Oberflächenbearbeitung KW - Strahlen KW - KorroPad PY - 2018 AN - OPUS4-46090 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Rosemann, Paul A1 - Müller, C. A1 - Roßberg, S. A1 - Pensel, P. A1 - Heyn, A. A1 - Burkert, Andreas T1 - Precipitation behavior and corrosion resistance of nickel-free, high-nitrogen austenitic stainless steels N2 - Nickel-free, nitrogen alloyed austenitic stainless-steels, with about 19 wt.-% Mn and 0,8 wt. % N, are an interesting alternative to classic CrNi austenitic stainless steels due to their superior mechanical properties (Rm > 900 MPa, A5 > 50 %, Av > 350 J) in the solution annealed condition. The formation of chromium-rich nitrides during suboptimal heat treatment, processing or application leads to an inhomogeneous distribution of alloying elements in the microstructure, which reduces the corrosion resistance. Consequently, an accurate knowledge of the sensitization behavior is indispensable for the use of nickel-free, high-nitrogen austenitic stainless steels. The relationship between artificial aging, phase formation and corrosion resistance was investigated on the alloys X8CrMnN18-19 (1.3815) and X8CrMnMoN18-19-2 (1.4456), both alloyed with 0,8 wt.-% Nitrogen, in the present work. The microstructural evolution was studied by LM and SEM while the corrosion resistance was characterized with the electrochemical potentiodynamic reactivation (EPR) and the KorroPad indicator-test. Both alloys showed increased corrosion susceptibility within critical aging parameters. Finally, a sensitization diagram was described successfully for both alloys showing the positive effect of molybdenum. T2 - Materials Science and Engineering 2018 (MSE) CY - Darmstadt, Germany DA - 26.09.2018 KW - Corrosion KW - Corrosion resistance KW - Heat treatment KW - KorroPad KW - Nitrogen KW - Pitting corrosion KW - Stainless steel KW - ThermoCalc PY - 2018 AN - OPUS4-46093 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -