Micromechanisms and modelling of crack initiation and growth in tool steels: role of primary carbides
-
Leon L. Mishnaevsky
,
Nils Lippmann
Abstract
Micromechanisms of damage initiation and crack growth in high speed and cold work steels are investigated using scanning electron microscopy in situ experiments. The role of primary carbides in initiation and growth of cracks in tool steels is clarified. It is shown that initial microcracks in the steels are formed in primary carbides and then join together. A hierarchical finite element model of damage initiation, which included a macroscopic model of the deformation of the specimen under real experimental conditions and a mesomechanical model of damage in real microstructures of steels, was developed. Using the hierarchical model, the conditions of local failure in the steels have been obtained. In order to study the effect of carbide arrangement on fracture, numerical simulations of fracture in steels with different ideal carbide arrangements were carried out and compared with each other. It is found that the heterogeneous arrangements of primary carbides can lead to strong deviations of a crack from the mode I path and, therefore, to a significant increase of the fracture energy of the steels.
Abstract
Mikromechanismen der Schädigungsinitiierung und -evolution in Schnellarbeits- und Kaltarbeitsstählen werden unter Verwendung von In-situ-Rasterelektronenmikroskopie-Biegeversuchen untersucht. Die Rolle der Primärkarbide bei der Schädigungsinitiierung und beim Risswachstum in Werkzeugsstählen wird geklärt. Es wurde gezeigt, dass sich die Anfangsmikrorisse in den Primärkarbiden bilden und dann zusammenwachsen. Ein hierarchisches Finite-Elemente-Modell der Schädigungsinitiierung, das auch das reale Mikrogefüge des Stahls berücksichtigt, wurde entwickelt. Mit dem Mesomodell wurden die lokalen Bruchbedingungen bestimmt. Um den Einfluss der Primärkarbidanordnungen auf das Bruchverhalten der Stähle zu untersuchen, wurden numerische Simulationen des Bruchs in Stählen mit unterschiedlichen idealen Karbidanordnungen durchgeführt und die Ergebnisse miteinander verglichen. Es wurde gefunden, dass die heterogenen Karbidverteilungen in den Stählen die starken Risspfadabweichungen von dem Mode-I-Risspfad verursachen und somit zu signifikant höheren Bruchenergien führen.
References
[1] L. Mishnaevsky Jr., S. Schmauder, in: P. Neumann et al. (Eds.), Steels and Materials for Power Plants, Proc. EUROMAT-99, Vol. 7, Wiley-VCH Verlag, Weinheim (1999) 269.10.1002/3527606181.ch48Search in Google Scholar
[2] H. Berns, C. Broeckmann, D. Weichert: Key Eng. Mater. 118 – 119 (1996) 163.10.4028/www.scientific.net/KEM.118-119.163Search in Google Scholar
[3] A. Gross–Weege, D. Weichert, C. Broeckmann: Comp. Mater. Sci. 5 (1996) 126.10.1016/0927-0256(95)00064-XSearch in Google Scholar
[4] A. Lehmann: Diploma Thesis, TU Bergakademie Freiberg (1995).Search in Google Scholar
[5] N. Lippmann, A. Lehmann, Th. Steinkopff, H.-J. Spies: Comp. Mater. Sci. 7 (1996)123.10.1016/S0927-0256(96)00071-7Search in Google Scholar
[6] N. Lippmann: Dissertation, Freiberg (1995).Search in Google Scholar
[7] Chr. Le Calvez, A. Ponsot, G.. Lichtenegger, L. Mishnaevsky Jr, S. Schmauder, I. Iturriza, M. Rodriguez Ibabe: Final Report RTD EU Project, Influence of Micromechanical Mechanisms of Strength and Deformation of Tool Steels under Static and Cyclic Load, Creusot Loire, France (2001).Search in Google Scholar
[8] L. Mishnaevsky Jr, N. Lippmann, S. Schmauder, in: Proc. 10th Int. Conf. Fracture, Honolulu, HA, CD-ROM (2001).Search in Google Scholar
[9] L. Mishnaevsky Jr., S. Schmauder: Appl. Mech. Rev. 54 (2001) 49.10.1115/1.3097288Search in Google Scholar
[10] L. Mishnaevsky Jr., M. Dong, S. Hoenle, S. Schmauder: Comp. Mater. Sci. 16 (1999)133.10.1016/S0927-0256(99)00055-5Search in Google Scholar
[11] L. Mishnaevsky Jr., U. Weber, N. Lippmann, S. Schmauder: in: M. Cross, J.W. Evans, C. Bailey (Eds.), Computational Modeling of Materials, Minerals, and Metals Processing, Proc. TMS Conference (2001) 673.Search in Google Scholar
[12] L. Mishnaevsky Jr., N. Lippmann, S. Schmauder: in: ASME Int. Mechanical Engineering Congress and Exposition, New York, CD, Vol. 2 (2001).Search in Google Scholar
[13] L. Mishnaevsky Jr.: Damage and Fracture of Heterogeneous Materials, Balkema, Rotterdam (1998).Search in Google Scholar
[14] H. Berns, A. Melander, D. Weichert, N. Asnafi, C. Broeckmann, A. Gross–Weege: Comp. Mater. Sci. 11 (1998) 166.10.1016/S0927-0256(98)00002-0Search in Google Scholar
© 2003 Carl Hanser Verlag, München
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- Notifications/Mitteilungen
- Personal/Personelles
- Books/Bücher
- Conferences/Konferenzen
Articles in the same Issue
- Frontmatter
- Articles/Aufsätze
- Bedeutung von Eigenspannungsabbau und mikrostrukturellen Veränderungen für die Lebensdauervorhersage schwingbeanspruchter Schweißverbindungen
- Factors affecting cyclic lifetime of EB-PVD thermal barrier coatings with various bond coats
- Depth-resolved X-ray residual stress analysis in PVD (Ti, Cr) N hard coatings
- Crystal orientation and residual stress in TiN film by synchrotron radiation
- Characterization of thermal and anodic oxide layers on β- and on near-β-titanium alloys for biomedical application
- Micromechanisms and modelling of crack initiation and growth in tool steels: role of primary carbides
- Fatigue crack nucleation at grain boundaries – experiment and simulation
- Fatigue and fracture-induced defect structures of metals investigated by positron microscopy
- Deformation and fracture of Nb/α-Al2O3 composites in compression and bending studied by optical methods
- Dislocation microstructures of single crystal ⟨001⟩ CMSX-4 specimens tensile tested at 700 and 1000°C
- Influence of mechanical surface treatments on the HCF performance of the Ni-superalloy Udimet 720 LI
- Precipitation of β-phase and twinning during deformation of Mg–Al alloy AZ91 at 150 °C after solution treatment
- Nanograin size, high-nitrogen austenitic stainless steels
- Der dynamische SD-Effekt und der Einfluss auf die Fließortkurve
- Einfluss der Umformgeschwindigkeit und -temperatur auf das Fließverhalten metallischer Werkstoffe
- Mean stress sensitivity of sintered iron and steel
- Thermozyklisches Kriechen einer kurzfaserverstärkten Aluminium-Kolbenlegierung
- Strength and ductility of thin Cu wires
- Modeling of deformation behavior of copper under equal channel angular pressing
- Reaktionssintern von AlMg–MgO zur Herstellung von Bauteilen auf Spinellbasis
- Determination of the local oxygen distribution in a commercial titanium alloy by 3-dimensional atom probe
- Phase diagram of the Al–Cu–Fe quasicrystal-forming alloy system
- Notifications/Mitteilungen
- Personal/Personelles
- Books/Bücher
- Conferences/Konferenzen
