TY - CONF A1 - Kauss, N. A1 - Halle, T. A1 - Rosemann, Paul T1 - Age-hardening behavior, 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 resistance 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 resistance due to chromium depletion. T2 - Materials Science and Engineering 2018 (MSE) CY - Darmstadt, Germany DA - 26.09.2018 KW - Corrosion KW - Corrosion resistance KW - Corrosion testing KW - EPR KW - Heat treatment KW - Martensitic stainless steels KW - REM KW - Stainless steel KW - ThermoCalc PY - 2018 AN - OPUS4-46094 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 - 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 - Kauss, N. A1 - Heyn, A. A1 - Rosemann, Paul T1 - How to Detect Sensitivity on Aged Lean-Duplex Stainless Steel With Electrochemical Methods N2 - The influence of isothermal ageing on microstructure, sensitisation and pitting corrosion resistance of the lean duplex stainless steel (LDSS) X2CrNiN23-4 was investigated with various electrochemical methods. The aging at 600 °C (from 0.1 h up to 20 h) lead to the formation of precipitations at the ferrite-ferrite (α/α) and ferrite-austenite (α/γ) grain boundaries, inducing sensitisation due to chromium depletion. The degree of sensitisation was evaluated with the double loop electrochemical potentiokinetic reactivation method (DL-EPR) according to ASTM G108 and correlated with critical pitting potentials (Epit) as well as critical pitting temperature (CPT) measured in an electrolyte according to ASTM G48 using electrochemical noise. Up to an ageing time of 1 h, the sensitisation did rise significantly, stabilising at a nearly constant level with a slight drop at 20 h. This behaviour correlated perfectly with the potentiodynamically determined pitting potentials Epit and sensitisation. The CPT showed a higher sensitivity at short ageing times compared to the DL-EPR and Epit. Finally, the KorroPad method was applied to visualise the sensitisation induced reduction of pitting corrosion resistance. The “KorroPad” is an agar-based gel-electrolyte containing 0.1 mol/l sodium chloride (NaCl) and 0.1 mol/l potassium ferricyanide III (K3[Fe(CN)6]), invented at the Federal Institute of Materials Research and Testing in Berlin (Germany) to detect surfaces of stainless steel prone to pitting corrosion. The standard configuration of the KorroPad showed no differentiation for the various aging conditions. Increasing the concentration of both NaCl and potassium ferrocyanide III to 0.5 M shifts the detection limit of the KorroPad method to stainless steels with higher corrosion resistance, producing the same trends detected by standard electrochemical pitting corrosion values (Epit, CPT) and sensitisation (DL-EPR). By that, the KorroPad method was successfully adjusted to the lean-duplex stainless steel X2CrNiN23-4, enabling short-time testing to detect sensitization. T2 - Electrochemical Methods in Corrosion Research 2018 CY - Cambridge, UK DA - 22.07.2018 KW - Corrosion testing KW - Duplex stainless steels KW - Corrosion KW - KorroPad KW - Pitting corrosion KW - EPR KW - Electrochemical noise KW - Stainless steel PY - 2018 AN - OPUS4-45615 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Rosemann, Paul A1 - Müller, C. A1 - Kauss, N. A1 - Halle, T. T1 - Application of the electrochemical potentiodynamic reactivation method on martensitic stainless steels N2 - The double loop electrochemical potentiodynamic reactivation (EPR) method is a standardised procedure for detecting and quantifying sensitisation on austenitic, ferritic and ferritic-austenitic stainless-steel grades. This sensitisation is caused by microstructural alternations, as the formation of chromium carbides, nitrides or sigma-phases, which generate local chromium depleted zones nearby. The latter strongly influence the corrosion resistance and the electrochemical response of a stainless steel during electrochemical potentiodynamic reactivation, providing important information on the degree of chromium depletion. In case of martensitic stainless steels, which are used for cutlery and surgical instruments, the heat treatment has a strong impact on the microstructure, the material properties and especially on the corrosion resistance. To study this interaction, the EPR method was modified for the application on martensitic stainless steels with about 13 wt.-% chromium. Different H2SO4 concentrations and EPR-parameters were tested and compared on two standard martensitic stainless-steel grades (AISI 420 A / X20Cr13 and AISI 420 C / X46Cr13) to define applicable parameters. Afterwards, these parameters were used to study the effect of austenitisation time and cooling rate on the corrosion resistance of both martensitic stainless steels. The response of both alloys was different due to the different carbon levels, which will be explained by microstructural investigations in detail. All results allow postulating a process window, in which chromium depletion is suppressed and an optimised corrosion resistance is guaranteed. Based on this research, the modified EPR-test is now used to control the heat treatment and its impact on the corrosion resistance of martensitic stainless steels in the cutlery industry. The EPR-test is thus an interesting alternative for manufacturers, processors, users and researchers to the time-consuming exposition test normally used to characterise the corrosion resistance of martensitic stainless steels. T2 - Electrochemical Methods in Corrosion Research 2018 CY - Cambridge, UK DA - 22.07.2018 KW - EPR KW - Corrosion resistance KW - Heat treatment KW - Stainless steels KW - Corrosion KW - Corrosion testing KW - Martensitic stainless steels PY - 2018 AN - OPUS4-45613 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR 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 JF - IOP Conference Series: Materials Science and Engineering 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 resistance 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 heattreated states. The results show that a work hardening accelerates the precipitation rate, while ageing at 600 °C reduces the corrosion resistance due to chromium depletion. T2 - WTK2018 CY - Chemnitz DA - 14.03.2018 KW - Corrosion KW - Corrosion resistance KW - Corrosion testing KW - EPR KW - Heat treatment KW - Stainless steel PY - 2018 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-452482 DO - https://doi.org/10.1088/1757-899X/373/1/012020 SN - 1757-899X SN - 1757-8981 VL - 373 SP - Article 012020, 1 EP - 9 PB - Institute of Physics CY - London AN - OPUS4-45248 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kauss, N. A1 - Rosemann, Paul T1 - Age-hardening behaviour, microstructure and corrosion resistance of the copper alloyed stainless steel 1.4542 T2 - Tagungsband zum 20. Werkstofftechnischen Kolloquium 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 resistance 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 chromi-um 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 hard-ening accelerates the precipitation rate, while ageing at 600 °C reduces the corrosion resistance due to chromium depletion. T2 - 20. Werkstofftechnisches Kolloquium CY - Chemnitz, Germany DA - 14.03.2018 KW - Corrosion KW - Corrosion resistance KW - Corrosion testing KW - EPR KW - Heat treatment KW - Stainless steel PY - 2018 SN - 978-3-00-058901-0 SN - 1439-1597 VL - 72 SP - 277 EP - 284 PB - Eigenverlag CY - Chemnitz AN - OPUS4-44558 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kauss, N. A1 - Rosemann, Paul 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 resistance 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 chromi-um 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 hard-ening accelerates the precipitation rate, while ageing at 600 °C reduces the corrosion resistance due to chromium depletion. T2 - 20. Werkstofftechnischen Kolloquium CY - Chemnitz, Germany DA - 14.03.2018 KW - Corrosion KW - Heat treatment KW - Stainless steel KW - Corrosion resistance KW - EPR KW - Corrosion testing PY - 2018 AN - OPUS4-44553 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -