TY - JOUR A1 - Kauss, Norman A1 - Heyn, A. A1 - Michael, O. A1 - Schymura, M. A1 - Rosemann, P. T1 - Application limits and sensitisation behaviour of the manganese- and nitrogen-alloyed austenitic stainless steel P2000 (X13CrMnMoN18-14-3) N2 - Nickel‐free high‐nitrogen‐alloyed stainless steels like the P2000 (X13CrMnMoN18‐14‐3) were developed to enhance the strength and corrosion resistance of austenitic stainless steels like 304 and 316 while keeping the typical high ductility. The mechanical and corrosive properties of P2000 were investigated and compared with 304 and 316 to highlight the application opportunities of this new alloy. The microstructure of the solution‐annealed condition was characterised by electron backscatter diffraction and the mechanical properties were studied by uniaxial tensile tests, Charpy impact tests and hardness measurements. The passivation behaviour was analysed using the electrochemical potentiodynamic reactivation, whereas the pitting corrosion resistance was compared by pitting potentials and pitting temperatures. However, secondary thermal influences or suboptimal heat treatment can impair the corrosion resistance due to the precipitation of secondary phases and the resulting sensitisation. Thermodynamic calculations and artificial ageing treatment in the range of 500–900°C for up to 100 h were used to determine critical time–temperature parameters for sensitisation. The microstructure of the various aged states was evaluated by scanning electron microscopy and compared with the degrading corrosion resistance characterised by the KorroPad method. KW - Austenitic stainless steel KW - Electrochemical methods KW - High‐nitrogen steel KW - Mechanical properties KW - Corrosion resistance PY - 2021 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-527925 DO - https://doi.org/10.1002/maco.202112450 VL - 71 IS - 10 SP - 1656 EP - 1667 PB - Wiley-VCH GmbH AN - OPUS4-52792 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 - 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 - Rosemann, P. A1 - Babutzka, Martin A1 - Heyn, Andreas A1 - Halle, T. T1 - Influence of heat treatment on corrosion resistance of martensitic stainless steels 1.4034 and 1.4021 N2 - In the last years, new approaches for the evaluation of the corrosion resistance of stainless steels were developed which allow short term corrosion testing with increased information content. This work analyses the extensive influence of heat treatment on microstructure and the resulting corrosion resistance of the martensitic stainless steels 1.4034 and 1.4021 with advanced methods. Different heat treatments at various austenitization temperatures up to 1100°C and the effect of different cooling rates were evaluated; the last has not yet been studied in literature at all. The resulting corrosion behaviour in relation to the different carbon content in the two used alloys and the applied heat treatment will be presented and discussed. The applied methods of investigation were conventional evaluation of the critical pitting corrosion potential (PP), modified electrochemical potentiodynamic reactivation (mEPR) and the "KorroPad" (KP) technique. The performance of modified EPR and its interpretation were optimized to provide additional information about the general passivation ability and the extent of chromium depletion as result of applied heat treatment. The aim using PP and KP was the correlation between the Parameters of the mEPR with the changes in the pitting corrosion resistance. Furthermore the results will demonstrate the functionality and usability of the short term corrosion test methods mEPR and KP in order to increase their acceptance within the scientific community. The results indicate a surprisingly large influence of both austenitization temperature and cooling rate on the corrosion resistance within all three used test methods, which can explain the different corrosion behaviour of martensitic stainless steels in earlier investigations. T2 - EUROCORR 2014 - European corrosion congress CY - Pisa, Italy DA - 08.09.2014 KW - Martensitic stainless steel KW - KorroPad KW - Pitting corrosion KW - Polarisation PY - 2014 SN - 978-3-89746-159-8 SP - O EP - 7455, 146 AN - OPUS4-31481 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Rosemann, P. A1 - Babutzka, Martin A1 - Müller, Thoralf A1 - Heyn, Andreas T1 - Einfluss von Mikrostruktur und Oberflächenbearbeitung auf die Korrosionsbeständigkeit martensitisch nichtrostender Stähle N2 - Die Qualität von Schneidwaren aus martensitisch nichtrostenden Stählen (MNS) hängt neben ihrer härtebedingten Schneidleistung wesentlich von ihrer Korrosionsbeständigkeit ab, die dauerhaft das hochwertige optische Erscheinungsbild gewährleisten soll. Zur Prüfung der Korrosionsbeständigkeit hat sich bei Schneidwaren aus MNS die Anwendung des Wechseltauchversuchs etabliert, dessen Ausweitung aufwendig und dessen Ergebnisse oftmals fragwürdig sind. In den letzten Jahren wurden daher neue elektrochemische Methoden entwickelt, um das Korrosionsverhalten von MNS objektiver zu bewerten. Diese neuen Untersuchungsmethoden ermöglichen eine genauere Erfassung der teilweise stark schwankenden Korrosionsbeständigkeit von MNS und bilden damit die Grundlage zur Aufklärung der Ursachen dieser Schwankungen. Im Rahmen des IGF-Vorhabens 16636 BG wurden dazu das elektrochemische Rauschen (ECR), das KorroPad und die elektrochemisch potentiodynamische Reaktivierung (EPR) eingesetzt, um die werkstoffseitigen Einflüsse der Mikrostruktur und den Einfluss der Oberflächenbearbeitung auf die Korrosionsbeständigkeit zu untersuchen. Es wurden dazu an drei weit verbreiteten MNS (1.4116, 1.4034 und 1.4021) je acht verschiedene Oberflächenzustände hergestellt und das Korrosionsverhalten untersucht. Um die dabei aufgetretenen Unterschiede im Lochkorrosionsverhalten zwischen den drei Werkstoffen zu erklären, wurde der EPR-Test eingesetzt, der lokale ChromVerarmung im Gefüge als werkstoffbedingte Ursache von Lochkorrosionsanfälligkeit nachweist. Mit der Kombination der Ergebnisse aus EPR, ECR und KorroPad war es möglich, die unterschiedliche Lochkorrosionsanfälligkeit direkt der unterschiedlich stark ausgeprägten Chromverarmung der drei MNS zuzuordnen. Der Einfluss der Chromverarmung auf die Lochkorrosionsanfälligkeit ist dabei deutlich größer als der Effekt der Oberflächenbearbeitung, der nur bei gering ausgeprägter Chromverarmung ersichtlich ist. Damit wurde gezeigt, dass nur bei Betrachtung aller Einflussgrößen sichere Aussagen zur Korrosionsbeständigkeit und zu den Ursachen der Lochkorrosionsanfälligkeit von MNS möglich sind. T2 - 15. Sommerkurs Werkstoffe und Fügen am Institut für Werkstoff- und Fügetechnik CY - Magdeburg, Germany DA - 12.09.2014 PY - 2014 SN - 978-3-940961-85-3 SP - 179 EP - 186 AN - OPUS4-31477 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Rosemann, P. T1 - In-vitro corrosion and biocompatibility study of coated MgCa1.0 magnesium alloys T2 - Eurocorr 2011 CY - Stockholm, Sweden DA - 2011-09-04 PY - 2011 AN - OPUS4-24467 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Rosemann, P. A1 - Bender, S. A1 - Heyn, Andreas A1 - Schmidt, J. T1 - In vitro corrosion and biocompatibility of coated MgCa1.0 magnesium alloys N2 - As bio-absorbable implant material the magnesium alloy Mg-1Ca is able to degrade in-vivo. The mechanical properties of this alloy are similar to those of human bone; both Mg and Ca are essential elements in human body. The main problem is the high corrosion rate of this alloy. Two coating systems based on plasma-chemical oxidation and an organic dip coating are applied onto MgCa1.0 magnesium alloy in order to slow down the corrosion rate. The corrosion behaviour of the coated alloys was investigated with electrochemical noise measurements. The influence of hydrogen evolution and increasing pH-value on the cytotoxicity was examined. The results of these investigations suggest that a combination of both coating systems leads to promising degradation properties. KW - Biocompatibility KW - Biodegradation KW - Magnesium KW - Plasma-Chemical Oxidation PY - 2011 DO - https://doi.org/10.4028/www.scientific.net/MSF.690.409 SN - 0255-5476 VL - 690 SP - 409 EP - 412 PB - Trans Tech Publications CY - Aedermannsdorf, Switzerland AN - OPUS4-23875 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Rosemann, P. A1 - Bender, S. A1 - Heyn, Andreas A1 - Schmidt, J. T1 - Korrosion and Biokompatibilität beschichteter MgCa1,0 Magnesiumlegierungen N2 - Die Magnesiumlegierung Mg-Cal besitzt als potentielles bioabsorbierbares Implantatmaterial die Möglichkeit, vollständig vom menschlichen Körper absorbiert zu werden. Die mechanischen Kennwerte dieser Legierung liegen im Bereich des menschlichen Knochens und beide Legierungselemente (Mg, Ca) sind essentielle Spurenelemente im menschlichen Organismus. Der limitierende Faktor für den Einsatz ist die hohe Degradationsrate dieser Legierung. Um die Degradationsgeschwindigkeit zu verringern, wurden zwei Beschichtungssysteme auf Grundlage der Plasmachemischen Oxidation (PCO) und organischer Beschichtung erzeugt und untersucht. Das Korrosionsverhalten dieser Schichtsysteme wurde dabei mit dem Elektrochemischen Rauschen analysiert. Zusätzlich wurde der Einfluss von Wasserstoffentwicklung und eines ansteigenden pHWert auf die Zelltoxizität untersucht. Die Ergebnisse zeigen, dass eine Kombination von beiden Schichtsystemen zu einem viel versprechenden Degradationsverhalten führt. T2 - 14. Sommerkurs Werkstoffe und Fügen am Institut für Werkstoff- und Fügetechnik CY - Magdeburg, Germany DA - 23.09.2011 KW - Magnesium KW - Magnesium-Calcium KW - Implantat KW - Beschichtung KW - Plasmachemische Oxidation KW - Korrosion KW - Elektrochemisches Rauschen PY - 2011 SN - 978-3-940961-56-3 SP - 135 EP - 138 AN - OPUS4-24491 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Rosemann, P. T1 - Qualitätsbeurteilung von Schneidwaren mittels Elektrochemischen Rauschen T2 - GfKORR-Jahrestagung 2012 CY - Frankfurt am Main, Germany DA - 2012-11-06 PY - 2012 AN - OPUS4-27047 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Rosemann, P. T1 - Short and long term evaluation of the degradation behaviour of Mg-1Ca magnesium alloys with combined coating systems T2 - Eurocorr 2012 CY - Istanbul, Turkey DA - 2012-09-09 PY - 2012 AN - OPUS4-26583 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Rosemann, P. A1 - Schmidt, J. A1 - Heyn, Andreas T1 - Short and long term degradation behaviour of Mg-1Ca magnesium alloys and protective coatings based on plasma-chemical oxidation and biodegradable polymer coating in synthetic body fluid N2 - The main problem limiting the application of magnesium alloys as biodegradable implant material is its high degradation rate. In order to slow down the corrosion rate an extrusion process and specific coating systems based on plasma-chemical oxidation (PCO) and organic dip coating with poly(ʟ-lactid-co-caprolacton) (PLLC) were applied on Mg–1Ca magnesium alloy. The additional PLLC coating is used to delay the start of substrate corrosion, while the purpose of the PCO coating is to decrease the substrate corrosion rate. The corrosion behaviour was investigated in synthetic body fluid (SBF) through measurement of the hydrogen evolution rate in long term tests and polarisation and electrochemical noise measurements in short term tests. The results showed significant differences between the cast and extruded alloys and a decrease of the corrosion rate due to corrosion product formation. The combination of both coating systems resulted in a significant delay of metal substrate corrosion and all coating systems showed good correlation between short and long term tests. The combination of the three investigation methods provides the possibility to gain more information about the degradation behaviour and break down of protective coatings. KW - Coatings KW - Corrosion KW - Electrochemical noise KW - Magnesium KW - Plasma-chemical oxidation PY - 2013 DO - https://doi.org/10.1002/maco.201206590 SN - 0947-5117 SN - 1521-4176 VL - 64 IS - 8 SP - 714 EP - 722 PB - Wiley-VCH Verl. CY - Weinheim AN - OPUS4-29074 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -