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VERSION:2.0
METHOD:PUBLISH
BEGIN:VEVENT
ORGANIZER;CN=ESTAD 2023:mailto:info@metec-estad.com
LOCATION:Room 16a
SUMMARY:Fatigue-oriented design of high-strength tools made of carbide-rich PM tool steels under multiaxial cyclic loading
DESCRIPTION:Improving the service life of cold forming tools is of great economic interest nowadays since productivity and resource efficiency significantly depend on tool life. High-performance, carbide-rich PM tool steels are often used in these applications, where tool service life is mainly limited by wear resistance and fatigue strength. Since cold working tools are usually subjected to non-proportional, multiaxial cyclic loadings during operations, a fatigue-oriented component design is essential along with a fundamental understanding of fatigue mechanisms. Currently, there are no validated, material-specific approaches for carbide-rich tool steels that consider the non-proportional multiaxiality or provide suitable fatigue strength data.
In this study, a new concept for tool design under multiaxial fatigue loading is developed and applied to an extruder screw and a twist drill. Various failure hypotheses such as the quadratic failure hypothesis (QFH), the FKM guideline hypothesis (FKM), the shear stress intensity hypothesis (SIH) or the normal stress hypothesis (NH) are investigated, and their accuracy is validated for the widely used PM tool steels AISI D2 (1.2379 / X153CrMoV12) and AISI M3 (1.3345 / HS6-5-3). Calculations are based on statistically validated uniaxial fatigue strengths (HCF, NG = 107) under axial and torsional loading, which are used in addition to the tensile strength for the construction of appropriate Haigh diagrams. For validation of the hypotheses, multiaxial fatigue tests are performed on a 2-axis hydraulic test rig to generate suitable multiaxial Wöhler diagrams.
The results indicate that both QFH and FKM provide quite good predictions of multiaxial fatigue strengths and are suitable for a design concept. The SIH mostly achieves poorer accuracy. The largest errors mostly occur with the NH. Overall, QFH, FKM and SIH show potential for accuracy improvements, e.g. through adjusting the weighting factors or including more precise Haigh diagram curves.

CLASS:PUBLIC
DTSTART:20230614T155000
DTEND:20230614T161000
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