TY - JOUR A1 - Ávila Calderón, Luis Alexander A1 - Rehmer, Birgit A1 - Schriever, Sina A1 - Ulbricht, Alexander A1 - Agudo Jácome, Leonardo A1 - Sommer, Konstantin A1 - Mohr, Gunther A1 - Skrotzki, Birgit A1 - Evans, Alexander T1 - Creep and creep damage behavior of stainless steel 316L manufactured by laser powder bed fusion JF - Materials Science and Engineering: A N2 - This study presents a thorough characterization of the creep properties of austenitic stainless steel 316L produced by laser powder bed fusion (LPBF 316L) contributing to the sparse available data to date. Experimental results (mechanical tests, microscopy, X-ray computed tomography) concerning the creep deformation and damage mechanisms are presented and discussed. The tested LPBF material exhibits a low defect population, which allows for the isolation and improved understanding of the effect of other typical aspects of an LPBF microstructure on the creep behavior. As a benchmark to assess the material properties of the LPBF 316L, a conventionally manufactured variant of 316L was also tested. To characterize the creep properties, hot tensile tests and constant force creep tests at 600 °C and 650 °C are performed. The creep stress exponents of the LPBF material are smaller than that of the conventional variant. The primary and secondary creep stages and the times to rupture of the LPBF material are shorter than the hot rolled 316L. Overall the creep damage is more extensive in the LPBF material. The creep damage of the LPBF material is overall mainly intergranular. It is presumably caused and accelerated by both the appearance of precipitates at the grain boundaries and the unfavorable orientation of the grain boundaries. Neither the melt pool boundaries nor entrapped gas pores show a significant influence on the creep damage mechanism. KW - 316L KW - Laser Powder Bed Fusion (LPBF) KW - Creep behavior KW - Additive Manufacturing KW - AGIL PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-539373 DO - https://doi.org/10.1016/j.msea.2021.142223 SN - 0921-5093 VL - 830 SP - 142223 PB - Elsevier B.V. AN - OPUS4-53937 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Ávila Calderón, Luis Alexander T1 - Creep behavior and microstructural evolution of LPBF 316L N2 - This presentation shows some experimental results of the characterization of the creep behavior of LPBF 316L, which has been poorly studied and understood to date. The presentation includes results regarding the mechanical properties, the initial microstructural state and its evolution under loading, and the damage mechanism. This work was done within the BAM focus area materials project AGIL. As a benchmark to assess the material properties of the LPBF 316L, a conventionally manufactured variant was also tested. T2 - 2nd Workshop on In-situ Monitoring and Microstructure Development in Additive Manufactured alloys at BAM CY - Online Meeting DA - 19.04.2021 KW - 316L KW - Additive Manufacturing KW - Creep behavior PY - 2021 AN - OPUS4-52682 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Ávila Calderón, Luis Alexander T1 - Mechanical behaviour of AM metals: Creep of LPBF 316L and low-cycle-fatigue of LMD Ti-6Al-4V N2 - Additively manufactured metallic materials have already started to find application in safety-relevant components. However, this has only happened for certain materials and specific applications and loading conditions, since there is still an extensive lack of knowledge as well as of historical data regarding their mechanical behaviour. This contribution aims to address this lack of understanding and historical data concerning the creep behaviour of the austenitic stainless steel 316L manufactured by Laser-Powder-Bed-Fusion (L-PBF) and the low-cycle-fatigue behaviour of the titanium alloy Ti-6Al-4V manufactured by Laser-Metal-Deposition (LMD). Furthermore, it aims to assess their mechanical behaviour against their conventional counterparts. With that in mind, specimens from conventional and additive materials are tested and their mechanical behaviour analysed based on characteristic curves. To understand the damage behaviours the materials are characterized by destructive and non-destructive techniques before and after failure. T2 - 1st Workshop on In-situ Monitoring and Microstructure Development in Additive Manufacturing CY - Online Meeting DA - 10.12.2020 KW - Ti-6Al-4V KW - 316L KW - Additive manufacturing KW - Creep behaviour KW - Low-cycle-fatigue behaviour PY - 2020 AN - OPUS4-51879 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Ávila Calderón, Luis Alexander A1 - Rehmer, Birgit A1 - Schriever, Sina A1 - Ulbricht, Alexander A1 - Agudo Jácome, Leonardo A1 - Sommer, Konstantin A1 - Mohr, Gunther A1 - Skrotzki, Birgit T1 - Kriech- und Bruchverhalten von additiv hergestelltem austenitischem Stahl 316L. Vergleich zum konventionellen Werkstoff. N2 - Eine kritische Aufgabe im Rahmen der Etablierung von Prozess-Struktur-Eigenschafts-Performance-Beziehungen bei der additiven Fertigung (AM) von Metallen ist die Ermittlung von zuverlässigen und gut dokumentierten Kennwerten zum Materialverhalten sowie das Schaffen von Wissen über die Struktur-Eigenschafts-Korrelation. Schließlich ist dies die Grundlage für die Entwicklung gezielterer Prozessoptimierungen und zuverlässigerer Lebensdauer-Vorhersagen. In diesem Zusammenhang zielt dieser Beitrag darauf ab, Daten und Erkenntnisse über das Kriechverhalten des austenitischen Edelstahls 316L zu liefern, der mittels Laser-Powder-Bed-Fusion (L-PBF) hergestellt wird. Um dieses Ziel zu erreichen, wurden Proben aus konventionellem warmgewalztem sowie AM-Material gemäß den bestehenden Normen für konventionelles Material geprüft und vor und nach dem Versagen mikrostrukturell charakterisiert. Die Probekörper wurden aus einzelnen Blöcken des AM-Materials gefertigt. Die Blöcke wurden mit einer Standard-Scan- und Aufbaustrategie hergestellt und anschließend wärmebehandelt. Das Kriechverhalten wird anhand der Kriechlebensdauer und ausgewählter Kriechkurven und Kennwerte beschrieben und vergleichend bewertet. Der Einfluss von Defekten und Mikrostruktur auf das Materialverhalten wird anhand von zerstörenden und zerstörungsfreien Auswertungen an ausgewählten Proben analysiert. Der AM-Werkstoff zeigt kürzere Kriechlebensdauern, erreicht das sekundäre Kriechstadium deutlich schneller und bei geringerer Dehnung und weist eine geringere Kriechduktilität im Vergleich zu seinem konventionellen Gegenstück auf. Das Kriechschädigungsverhalten des AM-Werkstoffs ist eher mikrostruktur- als defektgesteuert und ist durch die Bildung intergranularer Kriechrisse gekennzeichnet. Als kritische Merkmale werden die Versetzungsdichte sowie die Versprödung der Korngrenzen identifiziert. Die Mikro-Computertomographie (µCT) erweist sich als Alternative zur Metallographie, um die Kriechschädigung zu analysieren. T2 - Sitzung des DGM-Arbeitskreises Mechanisches Werkstoffverhalten bei hoher Temperatur CY - Online meeting DA - 07.10.2020 KW - 316L KW - Kriechen KW - Additive Fertigung KW - Mikrostruktur KW - Mikro-Computertomographie PY - 2020 AN - OPUS4-51824 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Ávila Calderón, Luis Alexander A1 - Rehmer, Birgit A1 - Schriever, Sina A1 - Ulbricht, Alexander A1 - Agudo Jácome, Leonardo A1 - Sommer, Konstantin A1 - Mohr, Gunther A1 - Skrotzki, Birgit T1 - Creep and fracture behavior of conventionally and additively manufactured stainless steel 316L N2 - A critical task within the frame of establishing process-structure-property-performance relationships in additive manufacturing (AM) of metals is producing reliable and well-documented material behavior’s data and knowledge regarding the structure-property correlation, including the role of defects. After all, it represents the basis for developing more targeted process optimizations and more reliable predictions of performance in the future. Within this context, this contribution aims to close the actual gap of limited historical data and knowledge concerning the creep behavior of the widely used austenitic stainless steel 316L, manufactured by Laser-Powder-Bed-Fusion (L-PBF). To address this objective, specimens from conventional hot-rolled and AM material were tested under application-relevant conditions according to existing standards for conventional material, and microstructurally characterized before and after failure. The test specimens were machined from single blocks from the AM material. The blocks were manufactured using a standard scan and build-up strategy and were subsequently heat-treated. The creep behavior is described and comparatively assessed based on the creep lifetime and selected creep curves and characteristic values. The effect of defects and microstructure on the material’s behavior is analyzed based on destructive and non-destructive evaluations on selected specimens. The AM material shows shorter creep lives, reaches the secondary creep stage much faster and at a lower strain, and features lower creep ductility compared to its conventional counterpart. The creep damage behavior of the AM material is more microstructure than defect controlled and is characterized by the formation and accumulation of single intergranular damage along the whole volume. Critical features identified are the grain morphology and the grain-boundary as well as the dislocation’s density. Micro-computed tomography (µCT) proves to be an alternative to metallography to analyze the creep damage. T2 - ASTM International Conference on Additive Manufacturing 2020 CY - Online meeting DA - 16.11.2020 KW - 316L KW - Creep behavior KW - Laser powder bed fusion KW - Additive manufacturing KW - Microstructure PY - 2020 AN - OPUS4-51823 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - THES A1 - Ávila Calderón, Luis Alexander T1 - Mechanisches Verhalten von additiv gefertigtem nichtrostendem Stahl X2CrNiMo17-12-2 (AISI 316L) und Vergleich zur konventionell gefertigten Variante T1 - Mechanical behavior of additively manufactured stainless steel X2CrNiMo17-12-2 (AISI 316L) and comparison with a conventionally manufactured variant N2 - Die additive Fertigung (AM) metallischer Werkstoffe ist eine Technologie, die zunehmend Gegenstand von Forschungsaktivitäten und industrieller Anwendung ist. Dennoch steht sie noch vor Herausforderungen, um eine breite Nutzung in sicherheitsrelevanten Anwendungen zu erreichen. Die Hauptgründe für die Verzögerung des technologischen Durchbruchs zugunsten von AM-Metallen gegenüber konventionell hergestellten Varianten sind das Fehlen eines tieferen Verständnisses der Prozess-Struktur-Eigenschafts-Beziehungen und die begrenzte Verfügbarkeit von Daten zu den Materialeigenschaften. In diesem Kontext stellt diese Arbeit einen Beitrag sowohl zum Verständnis der Prozess-Struktur-Eigenschafts-Beziehungen als auch zur Verbesserung der Datenlage von 316L dar, einem häufig als Konstruktionswerkstoff in verschiedenen Hochtemperaturbauteilen verwendeten Werkstoff. Die Arbeit legt den Fokus auf die mittels Laser-Pulverbettschmelzen hergestellte Werkstoffvariante, PBF-LB/M/316L. Eine konventionell hergestellte Variante, HR/316L, wurde auch untersucht. Bei PBF-LB/M/316L wurde zusätzlich der Effekt ausgewählter Wärmebehandlungen ausgewertet. Die Untersuchung umfasste die Charakterisierung der mechanischen Eigenschaften und der Verformungs- und Schädigungsmechanismen bei erhöhten Prüftemperaturen bei LCF und Kriechen, wo die Daten und Wissenslage am spärlichsten ist. Außerdem hat die untersuchte PBF-LB/M/316L-Wersktoffvariante einen geringen Porositätsgrad. Somit hat diese Arbeit die Mikrostruktur stärker in den Fokus genommen als die meisten bisher in der Literatur verfügbaren Studien. Die mechanische Prüfkampagne umfasste Zugversuche zwischen Raumtemperatur und 650 °C, LCF-Versuche zwischen Raumtemperatur und 600 °C sowie Kriechversuche bei 600 °C und 650 °C. In Ermangelung konkreter Richtlinien und Normen wurde die Charakterisierung zumeist anhand der bestehenden internationalen Prüfnormen und Probengeometrien durchgeführt. Aus jedem dieser Prüfverfahren wurden die entsprechenden Festigkeits- und Verformungskennwerte ermittelt. Darüber hinaus wurde mit Hilfe gezielter mikrostruktureller Untersuchungen ein Beitrag zum Verständnis des Zusammenhangs zwischen der Mikrostruktur und den mechanischen Eigenschaften in Bezug auf die Verformungs- und Schädigungsmechanismen geleistet. Die Dehngrenze von PBF-LB/M/316L ist etwa doppelt so hoch wie die von HR/316L und dieser Trend setzt sich mit ansteigender Prüftemperatur fort. Die Bruchdehnung ist bei allen Prüftemperaturen geringer. PBF-LB/M/316L weist über den größten Teil der Ermüdungslebensdauer vor allem bei Raumtemperatur höhere zyklische Spannungen als HR/316L auf. Ausschließlich bei den kleinsten Dehnungs-schwingbreiten sind die Ermüdungslebensdauer ausgeprägt kürzer. Das Wechselverformungsverhalten von PBF-LB/M/316L ist durch eine Anfangsverfestigung gefolgt von einer kontinuierlichen Entfestigung charakterisiert, welche bis zum Auftreten der zum Versagen führenden Entfestigung stattfindet. Die Kriechbruchzeiten und die Dauer jeder Kriechphase sind bei allen Kombinationen von Prüfparametern bei PBF-LB/M/316 kürzer als bei HR/316L. Die Spannungsabhängigkeit von PBF-LB/M/316L ist im Vergleich zu HR/316L geringer und die Duktilität beim Kriechen kleiner. Die minimale Kriechrate wird bei allen geprüften Parameterkombinationen bei deutlich geringeren Kriechdehnungen erreicht. Eine Wärmebehandlung bei 450 °C / 4 h bewirkt keine wesentliche Änderungen der Mikrostruktur und Zugversuchseigenschaften. Eine zusätzliche Wärmebehandlung bei 900 °C / 1 h verursacht eine Abnahme der Dehngrenze des PBF-LB/M/316L. Diese blieb aber immer noch um den Faktor 1,5x höher als bei HR/316L. Die Verformungsmerkmale wurden kaum davon beeinflusst. Bezüglich des Kriechverhaltens hat die Wärmebehandlung bei 900 °C / 1 h längere sekundäre und tertiäre Kriechstadien bewirkt und die Kriechdehnung hat sich signifikant erhöht. Die Bruchbilder unterscheiden sich generell nicht nur aber vor allem mit ansteigender Prüftemperatur, bei der bei PBF-LB/M/316L oft interkristalline Rissbildung beobachtet wurde. Die Zellstruktur trägt als der Hauptfaktor zu den unterschiedlichen mechanischen Eigenschaften im Vergleich zur HR/316L-Variante bei. Darüber hinaus spielen mutmaßlich die Kornmorphologie, die Stapelfehlerenergie und der Stickstoffgehalt eine Rolle. N2 - Metal additive manufacturing (AM) is a technology that is increasingly the subject of research activities and industrial applications. However, it still faces challenges to achieve widespread use in safety-relevant applications. The main reasons for the delay of this technological breakthrough in favor of AM metals over conventionally manufactured variants are the lack of a deeper understanding of process-structure-property relationships and the limited availability of data on material properties. In this context, this work contributes to both achieving a better understanding of process-structure-property relationships and the improvement of data for 316L, an alloy frequently used as a structural material in various high-temperature components. The work focuses on a material variant produced by laser pow-der bed fusion, PBF-LB/M/316L. A conventionally produced variant, HR/316L, was also investigated. For PBF-LB/M/316L, the effect of selected heat treatments was also evaluated. The investigation included the characterization of the mechanical properties and the related deformation and damage mechanisms at elevated test temperatures in LCF and creep, where data and knowledge are scarce. The PBF-LB/M/316L variant studied has a low degree of porosity. Thus, this work is more focused on the microstructure than most studies available in the literature. The mechanical test campaign included tensile tests between room temperature and 650 °C, LCF tests between room temperature and 600 °C, and creep tests at 600 °C and 650 °C. In the absence of concrete guidelines and standards for testing of AM metals, the characterization mostly took place using existing international test standards and specimen geometries. From each of the test methods, corresponding strength, and deformation characteristic values were determined. In addition, targeted microstructural investigations contributed to understanding the relationship between the microstructure and the mechanical properties in terms of deformation and damage mechanisms. The proof stress of PBF-LB/M/316L is about twice that of HR/316L. This trend remains with increasing test temperature. The elongation after fracture is lower at all test temperatures. Regarding LCF, PBF-LB/M/316L exhibits higher cyclic stresses than HR/316L for most of the fatigue life, especially at room temperature. Exclusively at the smallest strain amplitudes, the fatigue lives of PBF-LB/M/316L are markedly shorter than in HR/316L. The cyclic stress-strain deformation behavior of PBF-LB/M/316L features an initial strain hardening followed by a continuous softening, which occurs until the softening leading to failure takes place. The creep rupture times and the duration of each creep stage are shorter for PBF-LB/M/316 than for HR/316L for all combinations of test parameters. The stress dependence of PBF-LB/M/316L is lower, and the creep ductility is smaller compared to HR/316L. The minimum creep rate is reached at significantly lower creep extensions for all parameter combinations tested. A heat treatment at 450 °C / 4 h did not cause significant changes in the microstructure and tensile behavior. An additional heat treatment at 900 °C / 1 h caused a decrease in the proof stress of PBF-LB/M/316L. However, it still remained higher than the one of HR/316L by a factor of 1.5x. The deformation characteristics were hardly affected. Regarding the creep behavior, this latter heat treatment at 900 °C / 1 h caused longer secondary and tertiary creep stages, and the creep strain increased significantly. The fracture characteristics generally differed, which happened not only but especially with increasing test temperature, where intergranular cracking often took place in PBF-LB/M/316L. The cellular structure is considered the main factor contributing to the different mechanical properties compared to the HR/316L variant. In addition, grain morphology, stacking fault energy, and nitrogen content might play a role. KW - AGIL KW - Additive Fertigung KW - Laser-Pulverbettschmelzen KW - Mikrostrukturentwicklung KW - 316L KW - LCF KW - Kriechen KW - Additive Manufacturing KW - Microstructure KW - Mechanical Properties KW - Mechanische Eigenschaften PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-597143 DO - https://doi.org/10.14279/depositonce-19828 SP - 1 EP - 190 CY - Berlin AN - OPUS4-59714 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Winterkorn, R. A1 - Petrat, T. A1 - Gumenyuk, Andrey A1 - Rethmeier, Michael T1 - Temperature generation of different travel path strategies to build layers using laser metal deposition T2 - Lasers in Manufacturing Conference 2017 N2 - Laser Metal Deposition offers the chance to build near net shape parts. The temperature evolution within the process has an influence on track and layer geometries. There are special travel path strategies required to produce near net shape components and reduce shape deviation resulting of error propagation. This paper deals with the temperature progression of individual layers and the maximum heating of deeper substrate regions. Spiral and zig-zag strategies are examined. The investigations are carried out using S235JR as substrate and 316L as powder material. The influence of different strategies on temperature evolution is discussed. The results from the experiments show that various production strategies are associated with different temperature fields. Furthermore, the extent of the temperature variations of layer strategies and layer position are strongly dependent on the production direction. These results demonstrate the importance of developing suitable build-up strategies for parts of complex shape to ensure a stable process with constant temperature as well as even layers. T2 - Lasers in Manufacturing Conference 2017 CY - Munich, Germany DA - 26.06.2017 KW - 316L KW - Additive Manufacturing KW - Temperature behavior KW - Laser Metal Deposition KW - Stainless Steel KW - Edge effects PY - 2017 SP - 1 EP - 5 AN - OPUS4-42878 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Werner, Tiago A1 - Madia, Mauro A1 - Zerbst, Uwe T1 - Comparison of the fatigue behavior of wrought and additively manufactured AISI 316L JF - Procedia Structural Integrity N2 - Additive manufacturing (AM) is becoming increasingly important in engineering applications due to the possibility of producing components with a high geometrical complexity allowing for optimized forms with respect to the in-service functionality. Despite the promising potential, AM components are still far from being used in safety-relevant applications, mainly due to a lack of understanding of the feedstock-process-properties-performance relationship. This work aims at providing a full characterization of the fatigue behavior of the additively manufactured AISI 316L austenitic stainless steel and a direct comparison with the fatigue performance of the wrought steel. To this purpose, a set of specimens has been produced by laser powder bed fusion (L-PBF) and subsequently heat treated at 900 °C for 1 hour for complete stress relief, whereas a second set of specimens has been machined out of hot-rolled plates. Low cycle fatigue (LCF) and high cycle fatigue (HCF) tests have been conducted for characterizing the fatigue behavior. The L-PBF material had a higher fatigue limit and better finite life performance compared to wrought material. Both, LCF and HCF-testing revealed an extensive cyclic softening. T2 - FATIGUE DESIGN 2021 CY - Online meeting DA - 17.11.2021 KW - Additive manufacturing KW - L-PBF KW - 316L KW - Fatigue KW - LCF KW - HCF PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-544952 DO - https://doi.org/10.1016/j.prostr.2022.03.056 SN - 2452-3216 VL - 38 SP - 554 EP - 563 PB - Elsevier B.V. AN - OPUS4-54495 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Werner, Tiago A1 - Madia, Mauro A1 - Zerbst, Uwe A1 - Sprengel, Maximilian A1 - Ulbricht, Alexander A1 - Evans, Alexander T1 - Experimental investigation on cyclic R-curves for additively manufactured 316L steel N2 - The present study deals with the experimental characterization of short crack propagation in SLM (selective-laser-melting) manufactured stainless steel. More specifically, the determination of cyclic R-curves is discussed. This describes the dependency of the crack propagation threshold on crack growth during the short crack propagation stage. For metals, the threshold, starting at a material-intrinsic value, increases until it reaches a value independent of the crack length due to crack closure phenomena which build up at that stage. The cyclic R-curve, when used in the frame of a cyclic R curve analysis, characterizes the resistance of a material to fatigue crack growth and the ability to arrest a physically short crack. Thus, it is the link between classical fatigue and fracture mechanics. In the high-cycle-fatigue range, the short crack propagation stage dominates the overall lifetime, i.e., the number of cycles until failure. Below the fatigue limit crack arrest of hitherto propagable micro-cracks will occur. The effort for the experimental characterization of the short fatigue crack propagation behavior and the cyclic R-curve is very high compared to experiments on long crack propagation. A very exact measurement of crack extension is required, since small increments need to be depicted. Pre-cracking must leave a closure free initial crack, since closure must be build up only by the cyclic R-curve. The closure-free status is achieved by compression pre-cracking. The aim of the present study is an insight into the influence of an AM process on the short crack propagation threshold. Cyclic R-curves are experimentally determined at different load-ratios for 316L austenitic steel specimens produced by SLM and conventional manufacturing. Residual stresses are measured in the crack plane and their influence on the cyclic R-curve is discussed. T2 - ESIAM19 CY - Trondheim, Norway DA - 09.09.2019 KW - fatigue crack growth KW - Additive Manufacturing KW - 316L KW - Cyclic R-curve KW - Laser Powder Bed Fusion KW - AM KW - L-PBF PY - 2019 AN - OPUS4-49412 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Werner, Tiago ED - Madia, Mauro ED - Zerbst, Uwe T1 - Experimental investigation on cyclic R-curves for additively manufactured 316L steel N2 - The present study deals with the experimental characterization of short crack propagation in SLM (selective-laser-melting) manufactured stainless steel. More specifically, the determination of cyclic R-curves is discussed. This describes the dependency of the crack propagation threshold on crack growth during the short crack propagation stage. For metals, the threshold, starting at a material-intrinsic value, increases until it reaches a value independent of the crack length due to crack closure phenomena which build up at that stage. The cyclic R-curve, when used in the frame of a cyclic R curve analysis, characterizes the resistance of a material to fatigue crack growth and the ability to arrest a physically short crack. Thus, it is the link between classical fatigue and fracture mechanics. In the high-cycle-fatigue range, the short crack propagation stage dominates the overall lifetime, i.e., the number of cycles until failure. Below the fatigue limit crack arrest of hitherto propagable micro-cracks will occur. The effort for the experimental characterization of the short fatigue crack propagation behavior and the cyclic R-curve is very high compared to experiments on long crack propagation. A very exact measurement of crack extension is required, since small increments need to be depicted. Pre-cracking must leave a closure free initial crack, since closure must be build up only by the cyclic R-curve. The closure-free status is achieved by compression pre-cracking. The aim of the present study is an insight into the influence of an AM process on the short crack propagation threshold. Cyclic R-curves are experimentally determined at different load-ratios for 316L austenitic steel specimens produced by SLM and conventional manufacturing. Residual stresses are measured in the crack plane and their influence on the cyclic R-curve is discussed. T2 - ESIAM19 CY - Trondheim, Norway DA - 09.09.2019 KW - Fatigue crack growth KW - Additive Manufacturing KW - 316L KW - Cyclic R-curve KW - Laser Powder Bed Fusion KW - AM KW - L-PBF PY - 2019 SP - 1 EP - 8 AN - OPUS4-49416 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -