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The surface and subsurface conditions of components are critical for their functional properties. Every manufacturing process modifies the surface condition as a consequence of its mechanical, chemical, and thermal impact or combinations of the three. The depth of the affected zone varies for different machining operations and is related to the process parameters and characteristics. Furthermore, the initial material state has a decisive influence on the modifications that lead to the final surface conditions. With this knowledge, the collaborative research center CRC/Transregio 136 “Process Signatures” started a first joint investigation to analyze the influence of several machining operations on the surface modifications of uniformly premanufactured samples in a broad study. The present paper focusses on four defined process chains which were analyzed in detail regarding the resulting surface conditions as a function of the initial state. Two different workpiece geometries of the same initial material (AISI 4140, 42CrMo4 (1.7225) classified according to DIN EN ISO 683-2) were treated in two different heat treating lines. Samples annealed to a ferritic-perlitic microstructure were additionally deep rolled as starting condition. Quenched and tempered samples were induction hardened before further process application. These two states were then submitted to six different manufacturing processes, i.e., grinding (with mainly mechanical or thermal impact), precision turning (mainly mechanical), laser processing (mainly thermal), electrical discharge machining (EDM, mainly thermal) and electrochemical machining (ECM, (mainly chemical impact). The resulting surface conditions were investigated after each step of the manufacturing chain by specialized analysis techniques regarding residual stresses, microstructure, and hardness distribution. Based on the process knowledge and on the systematic characterizations, the characteristics and depths of the material modifications, as well as their underlying mechanisms and causes, were investigated. Mechanisms occurring within AISI 4140 steel (42CrMo4) due to thermal, mechanical or mixed impacts were identified as work hardening, stress relief, recrystallization, re-hardening and melting, grain growth, and rearrangement of dislocations.
Florian Borchers; Brigitte Clausen; Lisa Ehle; Marco Eich; Jérémy Epp; Friedhelm Frerichs; Matthias Hettig; Andreas Klink; Ewald Kohls; Yang Lu; Heiner Meyer; Bob Rommes; Sebastian Schneider; Rebecca Strunk; Tjarden Zielinski. The Influence of Former Process Steps on Changes in Hardness, Lattice and Micro Structure of AISI 4140 Due to Manufacturing Processes. Metals 2021, 11, 1102 .
AMA StyleFlorian Borchers, Brigitte Clausen, Lisa Ehle, Marco Eich, Jérémy Epp, Friedhelm Frerichs, Matthias Hettig, Andreas Klink, Ewald Kohls, Yang Lu, Heiner Meyer, Bob Rommes, Sebastian Schneider, Rebecca Strunk, Tjarden Zielinski. The Influence of Former Process Steps on Changes in Hardness, Lattice and Micro Structure of AISI 4140 Due to Manufacturing Processes. Metals. 2021; 11 (7):1102.
Chicago/Turabian StyleFlorian Borchers; Brigitte Clausen; Lisa Ehle; Marco Eich; Jérémy Epp; Friedhelm Frerichs; Matthias Hettig; Andreas Klink; Ewald Kohls; Yang Lu; Heiner Meyer; Bob Rommes; Sebastian Schneider; Rebecca Strunk; Tjarden Zielinski. 2021. "The Influence of Former Process Steps on Changes in Hardness, Lattice and Micro Structure of AISI 4140 Due to Manufacturing Processes." Metals 11, no. 7: 1102.
To generate advanced properties for the wear resistance and fatigue life of components and allow for an improved, application-oriented development of part specifications, a precisely tailored initial machining or manufacturing process is necessary. In addition, it is important to know how subsequent machining steps or operational loads affect the components’ condition. Residual stresses are a meaningful measurand for evaluating the modifications that a machining process induces into the material. The desired modifications should be specified regarding the final state for the required operational behavior. Thus, the stability of the modifications can be considered so that they can be beneficial in service. This investigation is part of fundamental research in the field of the Collaborative Research Center (CRC) “Process Signatures”. By applying defined selected loads, the effects on machined surface layers are investigated since machined components are exposed to further loads during use. For this reason, experimental process chains are applied in this work to grind-strengthened specimens as possible application cases and corresponding loads. These experimental process chains consist of defined mechanical and thermal loads, which are applied to the specimens using a thermal and mechanical testing system. Furthermore, it is investigated how these additional loads affect the modifications previously introduced by the grinding process. The influence of the additional loads is evaluated by using radiographic and electron microscopic examinations. It can be observed that the sequence, as well as the type of the applied loads, play a significant role in the development of the modifications.
Rebecca Strunk; Florian Borchers; Brigitte Clausen; Carsten Heinzel. Influence of Subsequently Applied Mechanical and Thermal Loads on Surfaces Ground with Mechanical Main Impact. Materials 2021, 14, 2386 .
AMA StyleRebecca Strunk, Florian Borchers, Brigitte Clausen, Carsten Heinzel. Influence of Subsequently Applied Mechanical and Thermal Loads on Surfaces Ground with Mechanical Main Impact. Materials. 2021; 14 (9):2386.
Chicago/Turabian StyleRebecca Strunk; Florian Borchers; Brigitte Clausen; Carsten Heinzel. 2021. "Influence of Subsequently Applied Mechanical and Thermal Loads on Surfaces Ground with Mechanical Main Impact." Materials 14, no. 9: 2386.
The material and its microstructure define the behaviour of a part in a deformation process. A single particle deformation process is introduced as a rapid material characterization method extending already existing approaches. Particle-oriented peening is performed with spherical micro samples of the low carbon steel 100Cr6 (AISI 52100) and the martensitic stainless steel X46Cr13 (AISI 420). Three different diameters (0.6 mm, 0.8 mm and 1.0 mm) were chosen to investigate the impact of the material and the surface to volume ratio. By processing single particles, the mechanical and geometrical properties of the particle before and after the impact can be linked to the deformation behaviour during the peening process. The elastic and plastic material properties are revealed by studying the remaining plastic deformation of the particle and the velocity reduction as a result of the impact. Instrumented universal micro hardness measurements are carried out to determine the hardness of the particles and to correlate it with the behavior of the particles during the particle-oriented peening process. The plastic deformation work as a characteristic value of micro hardness measurements of the different material states is discussed. It is conceivable that the consideration of different material behaviour related values (so-called descriptors) may replace conventional material testing in the future. Using short-term characterization methods like the particle-oriented peening a fast determination of material properties is possible.
Nicole Wielki; Heike Sonnenberg; Daniel Meyer; Brigitte Clausen. Particle-oriented peening as method to investigate the material dependent deformation behaviour. Journal of Materials Processing Technology 2020, 289, 116960 .
AMA StyleNicole Wielki, Heike Sonnenberg, Daniel Meyer, Brigitte Clausen. Particle-oriented peening as method to investigate the material dependent deformation behaviour. Journal of Materials Processing Technology. 2020; 289 ():116960.
Chicago/Turabian StyleNicole Wielki; Heike Sonnenberg; Daniel Meyer; Brigitte Clausen. 2020. "Particle-oriented peening as method to investigate the material dependent deformation behaviour." Journal of Materials Processing Technology 289, no. : 116960.
The surface and subsurface conditions of components are significant for their functional properties. Every manufacturing process step changes the surface condition due to its mechanical, chemical and/or thermal impact. The depth of the affected zone varies for different machining operations, and is predetermined by the process parameters and characteristics. Furthermore, the initial state has a decisive influence on the interactions that lead to the final surface conditions. The aim of the investigation presented here is to compare the influence of the load characteristics over the depth applied to manufactured components by several different machining operations and to determine the causing mechanisms. In order to ensure better comparability between the surface modifications caused by different machining operations, the same material was used (AISI 4140; German steel grade 42CrMo4 acc. to DIN EN 10083-3) and annealed to a ferritic-pearlitic microstructure. Based on interdisciplinary cooperation within the collaborative research center CRC/Transregio 136 “Process Signatures”, seven different manufacturing processes, i.e., grinding, turning, deep rolling, laser processing, inductive heat treatment, electrical discharge machining (EDM) and electrochemical machining (ECM), were used, and the resulting surface zones were investigated by highly specialized analysis techniques. This work presents the results of X-ray measurements, hardness measurements and electron microscopic investigations. As a result, the characteristics and depths of the material modifications, as well as their underlying mechanisms and causes, were studied. Mechanisms occurring within 42CrMo4 steel due to thermal, mechanical, chemical or mixed impacts were identified as phase transformation, solidification and strengthening due to dislocation generation and accumulation, continuum dynamic recrystallization and dynamic recovery, as well as chemical reactions.
Florian Borchers; Brigitte Clausen; Sandro Eckert; Lisa Ehle; Jeremy Epp; Simon Harst; Matthias Hettig; Andreas Klink; Ewald Kohls; Heiner Meyer; Markus Meurer; Bob Rommes; Sebastian Schneider; Rebecca Strunk. Comparison of Different Manufacturing Processes of AISI 4140 Steel with Regard to Surface Modification and Its Influencing Depth. Metals 2020, 10, 895 .
AMA StyleFlorian Borchers, Brigitte Clausen, Sandro Eckert, Lisa Ehle, Jeremy Epp, Simon Harst, Matthias Hettig, Andreas Klink, Ewald Kohls, Heiner Meyer, Markus Meurer, Bob Rommes, Sebastian Schneider, Rebecca Strunk. Comparison of Different Manufacturing Processes of AISI 4140 Steel with Regard to Surface Modification and Its Influencing Depth. Metals. 2020; 10 (7):895.
Chicago/Turabian StyleFlorian Borchers; Brigitte Clausen; Sandro Eckert; Lisa Ehle; Jeremy Epp; Simon Harst; Matthias Hettig; Andreas Klink; Ewald Kohls; Heiner Meyer; Markus Meurer; Bob Rommes; Sebastian Schneider; Rebecca Strunk. 2020. "Comparison of Different Manufacturing Processes of AISI 4140 Steel with Regard to Surface Modification and Its Influencing Depth." Metals 10, no. 7: 895.
For the establishment of a novel development process of new structural materials, short-term characterization methods capable of testing hundreds of spherical micro samples are needed. This paper introduces a compression test on spherical micro samples as a short-term characterization method to investigate the elastic-plastic deformation behavior. To demonstrate the potential of this newly developed method, the micro compression test is performed with a maximum loading of 300 N on 100Cr6 (AISI 52100 bearing steel) samples, with a diameter of 0.8 mm, in 15 different heat treatment conditions. The austenitizing temperature is varied between 800 and 1150 °C. Tempering of the samples is carried out in a differential scanning calorimetry process with temperatures of 180, 230 and 300 °C. Out of force-displacement curves and stress-strain relations, so-called descriptors (characteristic values) which are sensitive to the applied heat treatment can be extracted. The change of mechanical properties due to heat treatment and the resulting microstructure is presented by the trend of a stress descriptor in dependence of austenitizing and annealing temperature, which can be compared to the trend of the tensile strength as a material property obtained by conventional tensile tests. The trend of the descriptor determined in the compression test on spherical samples indicates the validity of this approach as a short-term characterization method.
Heike Sonnenberg; Brigitte Clausen. Short-Term Characterization of Spherical 100Cr6 Steel Samples Using Micro Compression Test. Materials 2020, 13, 733 .
AMA StyleHeike Sonnenberg, Brigitte Clausen. Short-Term Characterization of Spherical 100Cr6 Steel Samples Using Micro Compression Test. Materials. 2020; 13 (3):733.
Chicago/Turabian StyleHeike Sonnenberg; Brigitte Clausen. 2020. "Short-Term Characterization of Spherical 100Cr6 Steel Samples Using Micro Compression Test." Materials 13, no. 3: 733.
Today, micro components are used in various industrial sectors such as electronics engineering and medical applications. The final quality of such parts depends on each individual step of the production chain from the manufacturing of semi-finished parts to the post-processing. In this study, magnetron sputtering is used to manufacture thin (15-30 μm) aluminium-zirconium alloy foils for the deep drawing of high strength and hardenable micro cups, which can be, for example, employed as micro valve caps. The development of a novel process chain for the production of these parts includes four different steps, beginning with the production of Al-Zr foils by magnetron sputtering. Secondly, tensile tests are performed with the foils in order to estimate their mechanical properties. Subsequently, micro deep drawing is used to produce the cup’s shape, and finally, a heat treatment in a drop-down tube furnace adjusts the cup’s hardness during fall. It is shown in particular that Al-Zr foils produced by magnetron sputtering have an attractive cold forming and hardening potential due to a microstructure consisting essentially of an oversaturated solid solution of zirconium in the aluminium matrix. This material state enables adequate formability and simplifies the heat treatment process since no solution annealing is required.
Anastasiya Toenjes; Julien Kovac; Bernd Koehler; Axel Von Hehl; Andreas Mehner; Brigitte Clausen; Hans-Werner Zoch. Process chain for the fabrication of hardenable aluminium-zirconium micro-components by deep drawing. MATEC Web of Conferences 2018, 190, 15013 .
AMA StyleAnastasiya Toenjes, Julien Kovac, Bernd Koehler, Axel Von Hehl, Andreas Mehner, Brigitte Clausen, Hans-Werner Zoch. Process chain for the fabrication of hardenable aluminium-zirconium micro-components by deep drawing. MATEC Web of Conferences. 2018; 190 ():15013.
Chicago/Turabian StyleAnastasiya Toenjes; Julien Kovac; Bernd Koehler; Axel Von Hehl; Andreas Mehner; Brigitte Clausen; Hans-Werner Zoch. 2018. "Process chain for the fabrication of hardenable aluminium-zirconium micro-components by deep drawing." MATEC Web of Conferences 190, no. : 15013.
In the production of semi-finished products for the production of microcomponents and the components themselves, the characterization of their physical properties is of particular importance. Due to the often oligocrystalline character of these semi-finished products and components, it is necessary to use a suitable testing technique for static and dynamic investigations, as the mechanical properties are not transferable from the macroscopic point of view. In addition, the micro semi-finished products and components often show inhomogeneities induced by the manufacturing process. On the one hand, these are directly reflected in the microstructure and on the other hand they have an effect on quantities such as hardness or residual stresses, which play a decisive role in the application. Mechanical testing, conventional metallography, scanning electron microscopy (SEM), electron backscatter diffraction (EBSD), ultra-microhardness testing and X-ray residual stress analysis were used as measuring and analysis techniques suitable for the sub-millimeter range. In the following, the possibilities and limitations of two these methods are illustrated using the example of mechanical testing and EBSD. In this paper several examples for possible characterization techniques are given.
Bernd Köhler; Brigitte Clausen; Hans-Werner Zoch. Development and application of methods to characterize micro semi-finished products and micro components. MATEC Web of Conferences 2018, 190, 15012 .
AMA StyleBernd Köhler, Brigitte Clausen, Hans-Werner Zoch. Development and application of methods to characterize micro semi-finished products and micro components. MATEC Web of Conferences. 2018; 190 ():15012.
Chicago/Turabian StyleBernd Köhler; Brigitte Clausen; Hans-Werner Zoch. 2018. "Development and application of methods to characterize micro semi-finished products and micro components." MATEC Web of Conferences 190, no. : 15012.
Al-Sc-Zr alloys are interesting for the production of high strength micro components by micro deep drawing. These alloys show a good hardenability due to the formation of nanometer-scale spheroidal Al3(Sc, Zr) precipitates, which are highly coherent with the aluminum matrix. However, the formation of these precipitates in Al-Sc-Zr foils fabricated by conventional metallurgical methods dramatically reduces their ductility and drawability. In this work, magnetron sputtering was used to produce Al-Sc-Zr foils and Al-Sc-Zr / stainless steel bimetallic foils which are nearly free of these precipitates. Tensile tests were carried out to measure and compare the mechanical properties of monometallic Al-Sc-Zr foils and bimetallic Al-Sc-Zr / stainless steel foils deposited with varying plasma target powers and containing different volume fractions (layer thickness) of Al-Sc-Zr. Micro deep drawing was used to determine the drawability of selected monometallic and bimetallic foils. The results show that the density of monometallic Al-Sc-Zr foils can be improved significantly by increasing the DC target power and by using the high power impulse magnetron sputtering (HiPIMS) technology, resulting in foils with higher ductility. Bimetallic foils achieved higher strength and ductility than monometallic Al-Sc-Zr foils. Their mechanical properties vary with the target power and the volume fraction (thickness) of Al-Sc-Zr. The limit drawing ratio of HiPIMS deposited monometallic foil was 1.7 or 1.8 depending on the side of the foil facing the die, whereas a limit drawing ratio of 1.9 was observed for bimetallic foils.
Julien Kovac; Lukas Heinrich; Bernd Koehler; Andreas Mehner; Brigitte Clausen; Hans-Werner Zoch. Tensile properties and drawability of thin bimetallic aluminum-scandium-zirconium / stainless steel foils and monometallic Al-Sc-Zr fabricated by magnetron sputtering. MATEC Web of Conferences 2018, 190, 15001 .
AMA StyleJulien Kovac, Lukas Heinrich, Bernd Koehler, Andreas Mehner, Brigitte Clausen, Hans-Werner Zoch. Tensile properties and drawability of thin bimetallic aluminum-scandium-zirconium / stainless steel foils and monometallic Al-Sc-Zr fabricated by magnetron sputtering. MATEC Web of Conferences. 2018; 190 ():15001.
Chicago/Turabian StyleJulien Kovac; Lukas Heinrich; Bernd Koehler; Andreas Mehner; Brigitte Clausen; Hans-Werner Zoch. 2018. "Tensile properties and drawability of thin bimetallic aluminum-scandium-zirconium / stainless steel foils and monometallic Al-Sc-Zr fabricated by magnetron sputtering." MATEC Web of Conferences 190, no. : 15001.
In this investigation the influence of the inclusion type and size on the fatigue strength of different steels is analysed. As database case hardened, quenched and tempered as well as bearing steels in different heat treatment conditions, which have been investigated in several research projects over the last two decades, are used. Based on the approach of Murakami the local stress intensity at inclusions was determined to evaluate the influence of fracture causing inclusions on the fatigue strength. Different fatigue criteria have been used to calculate the local equivalent stress amplitudes considering residual stresses in the specimens, mean stresses during loading and multiaxial stresses in notched specimens. Since many run out specimens were subsequently fatigued at a higher stress amplitude, the critical inclusion type and size which have survived the initial stress amplitude could be determined. As a result the local stress intensity at inclusions which leads to no fatigue failure could be calculated as well. With the knowledge of the stress intensity factor range of the fractured and run out specimens a threshold stress intensity factor range could be derived for the different steels and inclusion sizes.
Jens Schumacher; Brigitte Clausen; Hans-Werner Zoch. Influence of inclusion type and size on the fatigue strength of high strength steels. MATEC Web of Conferences 2018, 165, 14003 .
AMA StyleJens Schumacher, Brigitte Clausen, Hans-Werner Zoch. Influence of inclusion type and size on the fatigue strength of high strength steels. MATEC Web of Conferences. 2018; 165 ():14003.
Chicago/Turabian StyleJens Schumacher; Brigitte Clausen; Hans-Werner Zoch. 2018. "Influence of inclusion type and size on the fatigue strength of high strength steels." MATEC Web of Conferences 165, no. : 14003.
Brigitte Clausen; Torben Karsch; Hans-Werner Zoch; John M. Beswick. High-Performance Bearing Steels: A New Approach in Alloy Development. Bearing Steel Technologies: 11th Volume, Advances in Steel Technologies for Rolling Bearings 2017, 343 -365.
AMA StyleBrigitte Clausen, Torben Karsch, Hans-Werner Zoch, John M. Beswick. High-Performance Bearing Steels: A New Approach in Alloy Development. Bearing Steel Technologies: 11th Volume, Advances in Steel Technologies for Rolling Bearings. 2017; ():343-365.
Chicago/Turabian StyleBrigitte Clausen; Torben Karsch; Hans-Werner Zoch; John M. Beswick. 2017. "High-Performance Bearing Steels: A New Approach in Alloy Development." Bearing Steel Technologies: 11th Volume, Advances in Steel Technologies for Rolling Bearings , no. : 343-365.
R. Strunk; B Clausen; H.-W Zoch. Structural Changes in the Surface Layer of Deep Rolled Samples Due to Thermal Loads. International Journal of Engineering Research and Applications 2017, 7, 86 -94.
AMA StyleR. Strunk, B Clausen, H.-W Zoch. Structural Changes in the Surface Layer of Deep Rolled Samples Due to Thermal Loads. International Journal of Engineering Research and Applications. 2017; 7 (1):86-94.
Chicago/Turabian StyleR. Strunk; B Clausen; H.-W Zoch. 2017. "Structural Changes in the Surface Layer of Deep Rolled Samples Due to Thermal Loads." International Journal of Engineering Research and Applications 7, no. 1: 86-94.
The Collaborative Research Center SFB/TRR 136 “Process Signatures”, located in Bremen, Aachen, Germany, and Stillwater, Oklahoma, USA, since 2014, aims to describe manufacturing processes by generated surface material modifications. The approach assumes that a general description allows generating desired surface properties with different equivalent machining or treatment strategies. The surface modification due to machining processes can have positive or negative influences on the life time behavior of components. An example for occurring surface modifications are residual stresses, known for being generated in surface regions due to machining operations. They are significantly influencing the properties of dynamically stressed components. Compressive stresses in general are known mostly to enhance the endurance limit due to counteracting crack formation and propagation. Tensile residual stresses in most cases reduce fatigue strength as they have to be superimposed to the crack initiating tensile load stresses. The aim of a holistic approach to surface treatment should therefore be, to a compressive residual stress depth profile adjusted to the anticipated demands. However, residual stresses are not stable. Due to temperature exposure or mechanical loads they can change within the lifetime of a component. This literature review aims to give an overview on the state of knowledge so far achieved on the stability of residual stresses and the dependence of their stability on the mode of generation.
B. Clausen; R. Strunk; Hans-Werner Zoch. The Dependence of Thermal and Mechanical Stability of Residual Stresses on Their Mode of Generation. HTM Journal of Heat Treatment and Materials 2016, 71, 251 -257.
AMA StyleB. Clausen, R. Strunk, Hans-Werner Zoch. The Dependence of Thermal and Mechanical Stability of Residual Stresses on Their Mode of Generation. HTM Journal of Heat Treatment and Materials. 2016; 71 (6):251-257.
Chicago/Turabian StyleB. Clausen; R. Strunk; Hans-Werner Zoch. 2016. "The Dependence of Thermal and Mechanical Stability of Residual Stresses on Their Mode of Generation." HTM Journal of Heat Treatment and Materials 71, no. 6: 251-257.
Julien Kovac; Jeremy Epp; Andreas Mehner; Bernd Köhler; Brigitte Clausen; Hans-Werner Zoch. On the potential of magnetron sputtering for manufacturing of thin high Mn TWIP steel foils. Surface and Coatings Technology 2016, 308, 136 -146.
AMA StyleJulien Kovac, Jeremy Epp, Andreas Mehner, Bernd Köhler, Brigitte Clausen, Hans-Werner Zoch. On the potential of magnetron sputtering for manufacturing of thin high Mn TWIP steel foils. Surface and Coatings Technology. 2016; 308 ():136-146.
Chicago/Turabian StyleJulien Kovac; Jeremy Epp; Andreas Mehner; Bernd Köhler; Brigitte Clausen; Hans-Werner Zoch. 2016. "On the potential of magnetron sputtering for manufacturing of thin high Mn TWIP steel foils." Surface and Coatings Technology 308, no. : 136-146.
Kurzfassung Für eine möglichst hohe Leistungsfähigkeit großer, einsatzgehärteter Wälzlager unter schwierigen Betriebsbedingungen, die Mangelschmierung und/oder Partikelüberrollung beinhalten, sind die Eigenschaften in der beanspruchten Randschicht der Wälzpartner entscheidend. Diese hängen wesentlich von der chemischen Zusammensetzung des Grundstahls und der Menge und Verteilung der eingebrachten Elemente Kohlenstoff bzw. Kohlenstoff und Stickstoff (Carbonitrieren) ab. Zur vergleichenden Untersuchung der Carbonitrierbarkeit wurden 11 Einsatz- und Vergütungsstähle mit unterschiedlichen Gaszusammensetzungen auf annähernd gleiche Einhärtetiefe carbonitriert. Die Randschichten wurden charakterisiert und ausgewählte Zustände wurden hinsichtlich der thermischen und mechanischen Stabilität überprüft. Ab- schließend erfolgte die Eignungsprüfung für Wälzlager anhand von Überrollungsprüfungen an Scheiben und Schrägkugellagern bei unterschiedlichen Überrollbedingungen. Das beste Gesamtergebnis unter Einbeziehung der Herstellungskosten erzielte der lufterschmolzene Stahl 32MnCrMo6–4–3 im carbonitrierten Zustand.
S. Rösch; W. Trojahn; B. Clausen. Carbonitrieren von Einsatz- und Vergütungsstählen für Lageranwendungen. HTM Journal of Heat Treatment and Materials 2016, 71, 51 -63.
AMA StyleS. Rösch, W. Trojahn, B. Clausen. Carbonitrieren von Einsatz- und Vergütungsstählen für Lageranwendungen. HTM Journal of Heat Treatment and Materials. 2016; 71 (1):51-63.
Chicago/Turabian StyleS. Rösch; W. Trojahn; B. Clausen. 2016. "Carbonitrieren von Einsatz- und Vergütungsstählen für Lageranwendungen." HTM Journal of Heat Treatment and Materials 71, no. 1: 51-63.
Wires with 1 mm initial diameter have been reduced between 10 and 64 percent at different temperatures and strain rates by infeed rotary swaging, which is an incremental cold forming process mainly used for rods and pipes. The volume fraction of martensite in the deformed wires has been determined by X-Ray diffraction and by magnetic induction for different processing parameters. Measurements show that for already small percentage of reduction, martensite is present in the wires and its amount changes with the strain rate and temperature. While for smaller strain rates at room temperature the formation of martensite is promoted, it is restrained for higher strain rates and higher temperatures. Results also reveal that the martensite distribution in the sample is inhomogeneous. Further investigations have been made to analyze the microstructure by optical microscopy and to determine mechanical properties by tensile testing.
Bernd Kuhfuss; Eric Moumi; Brigitte Clausen; Jérémy Epp; Bernd Koehler. Investigation of Deformation Induced Martensitic Transformation during Incremental Forming of 304 Stainless Steel Wires. Key Engineering Materials 2015, 651-653, 645 -650.
AMA StyleBernd Kuhfuss, Eric Moumi, Brigitte Clausen, Jérémy Epp, Bernd Koehler. Investigation of Deformation Induced Martensitic Transformation during Incremental Forming of 304 Stainless Steel Wires. Key Engineering Materials. 2015; 651-653 ():645-650.
Chicago/Turabian StyleBernd Kuhfuss; Eric Moumi; Brigitte Clausen; Jérémy Epp; Bernd Koehler. 2015. "Investigation of Deformation Induced Martensitic Transformation during Incremental Forming of 304 Stainless Steel Wires." Key Engineering Materials 651-653, no. : 645-650.
C. Stöberl; H. Bomas; Brigitte Clausen; F. Hoffmann; Hans-Werner Zoch. Untersuchungen zur Dauerfestigkeit carbonitrierter Proben aus den Einsatzstählen 18CrNiMo7-6und 20MnCr5. Materialwissenschaft und Werkstofftechnik 2015, 46, 533 -549.
AMA StyleC. Stöberl, H. Bomas, Brigitte Clausen, F. Hoffmann, Hans-Werner Zoch. Untersuchungen zur Dauerfestigkeit carbonitrierter Proben aus den Einsatzstählen 18CrNiMo7-6und 20MnCr5. Materialwissenschaft und Werkstofftechnik. 2015; 46 (6):533-549.
Chicago/Turabian StyleC. Stöberl; H. Bomas; Brigitte Clausen; F. Hoffmann; Hans-Werner Zoch. 2015. "Untersuchungen zur Dauerfestigkeit carbonitrierter Proben aus den Einsatzstählen 18CrNiMo7-6und 20MnCr5." Materialwissenschaft und Werkstofftechnik 46, no. 6: 533-549.
J. Schumacher; Brigitte Clausen; Hans-Werner Zoch. Strength and failure behaviour of carbon fibre reinforced plastics (CFRP)-aluminium seam structures. Materialwissenschaft und Werkstofftechnik 2014, 45, 1108 -1115.
AMA StyleJ. Schumacher, Brigitte Clausen, Hans-Werner Zoch. Strength and failure behaviour of carbon fibre reinforced plastics (CFRP)-aluminium seam structures. Materialwissenschaft und Werkstofftechnik. 2014; 45 (12):1108-1115.
Chicago/Turabian StyleJ. Schumacher; Brigitte Clausen; Hans-Werner Zoch. 2014. "Strength and failure behaviour of carbon fibre reinforced plastics (CFRP)-aluminium seam structures." Materialwissenschaft und Werkstofftechnik 45, no. 12: 1108-1115.
Kurzfassung Das Laserstrahlbeschichten wird als Reparaturverfahren von Bauteilen und zur Auftragung von Funktionsschichten eingesetzt. Über die Ermüdungseigenschaften laserstrahlbeschichteter Bauteile existieren jedoch nur wenige Untersuchungen. Aus diesem Grund wird in dieser Veröffentlichung das Ermüdungsverhalten von Vierpunktbiegeproben aus dem Vergütungsstahl 42CrMo4 und dem austenitischen Stahl X5CrNi18-10 untersucht, die mit der Kobalt-Chrom-Legierung Stellite 21 laserstrahlbeschichtet wurden. Hierbei zeigte sich, dass der Kernwerkstoff einen entscheidenden Einfluss auf die Wechselfestigkeit der Proben hat. Die Proben aus X5CrNi18-10 erreichten mehr als die doppelte Wechselfestigkeit der Proben aus 42CrMo4, was auf unterschiedliche Eigenspannungszustände in der Beschichtung zurückgeführt wird. Bei den Proben aus 42CrMo4 zeigten thermische Nachbehandlungsverfahren keinen Einfluss auf die Wechselfestigkeit, während sich nach einer mechanischen Nachbehandlung durch Festwalzen die Wechselfestigkeit der Proben um den Faktor zwei steigerte.
J. Schumacher; H. Köhler; B. Clausen; Hans-Werner Zoch. Einflussfaktoren auf die Wechselfestigkeit laserstrahlbeschichteter Proben. HTM Journal of Heat Treatment and Materials 2014, 69, 282 -294.
AMA StyleJ. Schumacher, H. Köhler, B. Clausen, Hans-Werner Zoch. Einflussfaktoren auf die Wechselfestigkeit laserstrahlbeschichteter Proben. HTM Journal of Heat Treatment and Materials. 2014; 69 (5):282-294.
Chicago/Turabian StyleJ. Schumacher; H. Köhler; B. Clausen; Hans-Werner Zoch. 2014. "Einflussfaktoren auf die Wechselfestigkeit laserstrahlbeschichteter Proben." HTM Journal of Heat Treatment and Materials 69, no. 5: 282-294.
The average operation temperature of rolling element bearings in standard applications is rising. Due to this advancing demand, the chemical composition of martensitic bearing steels like 100Cr6 (DIN 1.3505; SAE 52100) and 100CrMnSi6-4 (DIN 1.3520) has to be adapted. To enhance the tempering resistance of these steels several alloying approaches concerning the contents of silicon and manganese were tested. The central point of interest in the presented investigation was the influence of the new alloy concept on the lifetime of ball bearings. It could be shown that the lifetime of artificially damaged bearings containing 1.5 % silicon is significantly higher compared to alloys with lower silicon contents. At test temperatures of 120°C and Hertzian contact stresses of approximately 3200 and 3400 MPa, the L50 lifetime was about three times higher with 1.5 % silicon alloyed steels. The further characterization of the investigated alloys consisted of soft turning and hard grinding tests, of stress–strain tests, fatigue tests, and bearing tests with ball bearings type 6206. The results of the turning and grinding tests showed no significant influence of the alloying elements up to 1.5 % silicon and 1.1 % manganese. The parameters of the stress–strain curves showed a small influence of the silicon content, which is dominated by the influence of the heat treatment parameters. The change in the retained austenite content and therewith in the mechanical properties due to different tempering procedures is characteristically reduced with the high silicon content of 1.5 %.
Brigitte Clausen; Christoph Stöberl; Werner Trojahn; Hans-Werner Zoch. Improved Chemical Composition of Low Alloyed High Carbon Martensitic Bearing Steels for Higher Fatigue Strength. Bearing Steel Technologies: 10th Volume, Advances in Steel Technologies for Rolling Bearings 2014, 1 -21.
AMA StyleBrigitte Clausen, Christoph Stöberl, Werner Trojahn, Hans-Werner Zoch. Improved Chemical Composition of Low Alloyed High Carbon Martensitic Bearing Steels for Higher Fatigue Strength. Bearing Steel Technologies: 10th Volume, Advances in Steel Technologies for Rolling Bearings. 2014; ():1-21.
Chicago/Turabian StyleBrigitte Clausen; Christoph Stöberl; Werner Trojahn; Hans-Werner Zoch. 2014. "Improved Chemical Composition of Low Alloyed High Carbon Martensitic Bearing Steels for Higher Fatigue Strength." Bearing Steel Technologies: 10th Volume, Advances in Steel Technologies for Rolling Bearings , no. : 1-21.
Kurzfassung Hoch belastete Zahnräder werden üblicherweise wärmebehandelt, um den betriebsbedingten Belastungen zu widerstehen. Im Zusammenhang mit Bauteilen des Antriebstrangs, insbesondere Zahnrädern, wird häufig das Verfahren des Einsatzhärtens eingesetzt. Dabei werden verschiedene Verzüge beobachtet, deren Untersuchung im Folgenden dargestellt wird. Als Probekörper dienten schrägverzahnte kleinmodulige Stirnräder. Die Einsatzhärtung wurde in einer Zwei-Kammer-Vakuumanalage vom Typ IPSEN RVTC 224 mittels Niederdruckaufkohlen und Hochdruckgasabschreckung durchgeführt. Die Untersuchungen wurden durch die Anwendung von Design-of-Experiments (DoE)-Methoden unterstützend begleitet. Bezüglich ihres Einflusses auf den Verzug der Zahnräder standen die drei aufeinanderfolgenden Wärmebehandlungsschritte Erwärmen, Aufkohlen und Abschrecken im Fokus der Untersuchungen. Die in den Untersuchungen des Erwärmprozesses variierten Parameter sind der Chargenaufbau, der Wärmeübergangsmechanismus sowie die Temperatur der ersten Haltestufe für den Temperaturausgleich in der Charge. Die in der Aufkohlung variierten Größen sind die Aufkohlungstiefe und der Randkohlenstoffgehalt sowie die Atmosphäre während der Diffusions- und Haltephasen. Das Abschrecken wurde nicht variiert. Die Änderung der Maß- und Formabweichungen durch die Wärmebehandlung wurde durch 3-D-Koordinatenmessung des Grundkörpers und der Verzahnung vor und nach der Wärmebehandlung ermittelt. Die Einflüsse der untersuchten Parameter auf die Maß- und Formänderungen der Zahnräder wurden durch eine Varianzanalyse der Versuchsergebnisse statistisch bewertet und die Signifikanz verifiziert.
Matthias Steinbacher; Holger Surm; Brigitte Clausen; Th. Lübben; Franz Hoffmann. Systematische Untersuchung verschiedener Einflussgrößen auf die Maß- und Formänderungen von einsatzgehärteten Stirnrädern*. HTM Journal of Heat Treatment and Materials 2012, 67, 65 -78.
AMA StyleMatthias Steinbacher, Holger Surm, Brigitte Clausen, Th. Lübben, Franz Hoffmann. Systematische Untersuchung verschiedener Einflussgrößen auf die Maß- und Formänderungen von einsatzgehärteten Stirnrädern*. HTM Journal of Heat Treatment and Materials. 2012; 67 (1):65-78.
Chicago/Turabian StyleMatthias Steinbacher; Holger Surm; Brigitte Clausen; Th. Lübben; Franz Hoffmann. 2012. "Systematische Untersuchung verschiedener Einflussgrößen auf die Maß- und Formänderungen von einsatzgehärteten Stirnrädern*." HTM Journal of Heat Treatment and Materials 67, no. 1: 65-78.