TY - GEN A1 - Pyzalla, A. A1 - Pinto, H. A1 - Wild, E. A1 - Poeste, T. A1 - Bohne, C. A1 - Reimers, W. A1 - Aßmus, Kristin A1 - Hübner, Wolfgang A1 - Fischer, A. ED - Bartz, Wilfried J. T1 - Mechanical Stress in Tribo-Layers T2 - 14th International Colloquium Tribology "Tribology and Lubrication Engineering" CY - Stuttgart, Deutschland DA - 2004-01-13 PY - 2004 SN - 3-924813-54-X VL - I SP - 85 EP - 89 PB - Techn. Akad. Esslingen CY - Ostfildern AN - OPUS4-3144 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Pinto, H. A1 - Pyzalla, A.R. A1 - Büscher, R. A1 - Fischer, A. A1 - Aßmus, Kristin A1 - Hübner, Wolfgang T1 - The effect of hydrogen on the deterioration of austenitic steels during wear at cryogenic temperature N2 - Hydrogen represents an important alternative to fossil fuels. Hydrogen storage is possible as a gas, at room temperature (RT) at about 20 MPa pressure, and in a liquefied form, at cryogenic temperatures of about 20 K. The latter form is particularly attractive due to the possibility of stocking a large quantity of hydrogen within a small volume. In moving parts (e.g. of transport vehicles) cryogenic temperature and the presence of hydrogen strongly enhance wear processes and subsequently component failure. The present work deals with the deformation behaviour and the microstructural deterioration of austenitic CrNi- and CrMn high nitrogen-steels during friction in liquid hydrogen at 20 K. The modified microstructure within the wear scar is studied by scanning electron microscopy and X-ray diffraction methods. Diffraction studies of wear scars reveal the importance of twinning during deformation at 20 K. This increase of twinning can be attributed to a hydrogen-induced reduction of stacking fault energy (SFE) in the austenitic steels. Interactions between twin boundaries and planar dislocation structures along with locally increased stresses led to the formation of extensive crack networks. The amount of hydrogen-induced surface cracks depends on the alloy composition and is not necessarily correlated to the wear resistance of the austenitic steels. KW - Austenitic steel KW - Stacking fault energy KW - Hydrogen KW - Wear KW - Cryotechnology PY - 2005 DO - https://doi.org/10.1016/j.wear.2005.02.057 SN - 0043-1648 VL - 259 IS - 1-6 SP - 424 EP - 431 PB - Elsevier CY - Amsterdam AN - OPUS4-7692 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Österle, Werner A1 - Rooch, Heidemarie A1 - Pyzalla, A. A1 - Wang, L. T1 - Investigation of white etching layers on rails by optical microscopy, electron microscopy, X-ray and synchrotron X-ray diffraction N2 - Patches of white etching layers on rail surfaces were investigated using sophisticated techniques like cross-sectional transmission electron microscopy (XTEM) and synchroton X-ray diffraction. Optical microscopy failed to resolve the microstructure, but in the TEM submicron grains with high dislocation densities and occasional twins, which are characteristic features of high carbon martensite, were observed. The martensitic structure was confirmed by evaluation of synchroton X-ray diffraction line profiles. The latter technique also allowed to determine dislocation densities of the order of 1012 cm-2 and residual compressive stresses of about 200 MPa. KW - Cross-sectional transmission electron microscopy KW - White etching layers KW - X-ray diffraction PY - 2001 DO - https://doi.org/10.1016/S0921-5093(00)01842-6 SN - 0921-5093 SN - 1873-4936 VL - 303 SP - 150 EP - 157 PB - Elsevier CY - Amsterdam AN - OPUS4-2370 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Pyzalla, A. T1 - Mechanical Stress in Tribo-Layers T2 - 14th International Colloquium Tribology CY - Ostfildern, Germany DA - 2004-01-13 PY - 2004 AN - OPUS4-3152 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hübner, Wolfgang A1 - Gradt, Thomas A1 - Aßmus, Kristin A1 - Pyzalla, A. A1 - Pinto, H. A1 - Stuke, S. T1 - Hydrogen absorption by steels during friction T2 - Hydrogen and Fuel Cells Conference and Trade Show ; Hydrogène et Piles à Combustible Conférence et Foire Commerciale CY - Vancouver, Canada DA - 2003-06-08 PY - 2003 SP - 1 EP - 11(?) PB - CHA CY - Toronto AN - OPUS4-3319 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Hübner, Wolfgang A1 - Pyzalla, A. A1 - Aßmus, Kristin A1 - Wild, E. A1 - Wroblewski, T. T1 - Phase stability of AISI 304 stainless steel during sliding wear at extremely low temperatures N2 - For applications at extremely low temperatures of a few Kelvin, austenitic FeCrNi alloys usually are employed due to their beneficial mechanical and magnetic properties. These properties depend on the stability of the austenitic microstructure, since transformation into martensite leads to a loss of ductility as well as to the formation of ferromagnetic regions. The necessary conditions for the transformation into martensite are present in case of components subjected to friction, e.g. in machine parts used for transportation of cryogens, especially of liquid hydrogen. The transformation behaviour at low temperatures is studied on friction stressed FeCrNi steel AISI 304 by magnetic measurements and by diffraction methods. T2 - Wear of Materials CY - Washington D.C., USA DA - 2003-03-30 KW - Stainless steel KW - Cryoengineering KW - Friction KW - Phase transformation PY - 2003 DO - https://doi.org/10.1016/S0043-1648(03)00164-9 SN - 0043-1648 VL - 255 IS - 1 SP - 476 EP - 480 PB - Elsevier CY - Amsterdam AN - OPUS4-2629 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Hübner, Wolfgang A1 - Aßmus, Kristin A1 - Pyzalla, A. A1 - Pinto, H. ED - Marini, M. T1 - Hydrogen uptake in stainless steels at low temperatures T2 - 5. HYPOTHESIS ; 5th International Conference HYPOTHESIS ; 5e Congresso Internazionale HYPOTHESIS CY - Porto Conte, Italy DA - 2003-09-07 KW - Stainless steel KW - Low temperature KW - Friction KW - Liquid hydrogen KW - Hydrogen absorption PY - 2003 SN - 88-86281-90-0 VL - 5 SP - 581 EP - 588 PB - SGEditoriali CY - Padova AN - OPUS4-3499 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Hübner, Wolfgang A1 - Pyzalla, A. T1 - Friction and wear behaviour of stainless steels in liquid hydrogen T2 - 14th World Conference on Energetic Hydrogen ; 14th World Hydrogen Energy Conference ; 14e Conférence Mondiale de l'Hydrogène Énergétique CY - Montréal, Canada DA - 2002-06-09 PY - 2002 SN - 2-9214505-60-1 PB - Canadian Hydrogen Association CY - Montreal AN - OPUS4-1868 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Aßmus, Kristin A1 - Hübner, Wolfgang A1 - Pyzalla, A.R. A1 - Pinto, H.C. ED - Bartz, Wilfried J. T1 - Structure Transformations in CrNi Steels under Tribological Stressing at Low Temperatures T2 - 14th International Colloquium Tribology, Tribology and Lubrication Engineering CY - Stuttgart, Germany DA - 2004-01-13 PY - 2004 SN - 3-924813-54-X VL - 2 SP - 1047 EP - 1054 PB - Techn. Akad. Esslingen CY - Ostfildern AN - OPUS4-3055 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Pinto, H. A1 - Pyzalla, A.R. A1 - Hübner, Wolfgang A1 - Aßmus, Kristin T1 - Influence of Environment, Temperature and Chemical Composition on the Microstructural Deterioration of CrNi Steels during Friction KW - CrNi steel KW - Stacking fault energy KW - Phase transformation KW - Friction KW - Cryotechnology PY - 2004 SN - 0933-5137 SN - 1521-4052 VL - 35 IS - 10/11 SP - 716 EP - 721 PB - Wiley-VCH Verl. CY - Weinheim AN - OPUS4-6867 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Aßmus, Kristin A1 - Hübner, Wolfgang A1 - Pyzalla, A.R. A1 - Pinto, H. T1 - Structure Transformations in CrNi Steels under Tribological Stressing at Low Temperatures KW - Tribologie KW - Tiefe Temperaturen KW - Austenitische Stähle KW - Martensitbildung PY - 2006 SN - 1354-4063 SN - 1557-685X VL - 12 IS - 2 SP - 149 EP - 159 PB - Coppin CY - Deal AN - OPUS4-14584 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -