Material Characterization and Modeling for Finite Element Simulation of Press Hardening with AISI 420C

authored by
Bernd-Arno Behrens, Daniel Rosenbusch, Hendrik Wester, Eugen Stockburger
Abstract

The process of press hardening is gaining importance in view of the increasing demand for weight reduction combined with higher crash safety in cars. An alternative to the established manganese-boron steel 22MnB5 is hot-formed martensitic chromium steels such as AISI 420C. Strengths of 1850 MPa and elongations of 12% are possible, exceeding those of 22MnB5. In industrial manufacturing, FE-simulation is commonly used in order to design car body parts cost-efficiently. Therefore, the characterization and the modeling of AISI 420C regarding flow stress, phase transformations as well as failure behavior are presented in this paper. Temperature-depended flow curves are determined, showing the low flow stress and hardening behavior at temperatures around 1000 °C. Cooling experiments are carried out, and a continuous cooling diagram is generated. Observed phases are martensite and retained austenite for industrial relevant cooling rates above 10 K/s. In addition, tests to investigate temperature-dependent forming limit curves are performed. As expected, the highest forming limit is reached at 1050 °C and decreases with falling temperature. Finally, a simulation model of a press-hardening process chain is set up based on the material behavior characterized earlier and compared to experimental values. The forming force, phase transformation and forming limit could be calculated with good agreement to the experiment.

Organisation(s)
Institute of Metal Forming and Metal Forming Machines
Type
Article
Journal
Journal of Materials Engineering and Performance
Volume
31
Pages
825-832
No. of pages
8
ISSN
1059-9495
Publication date
01.2022
Publication status
Published
Peer reviewed
Yes
ASJC Scopus subject areas
General Materials Science, Mechanics of Materials, Mechanical Engineering
Electronic version(s)
https://doi.org/10.1007/s11665-021-06216-y (Access: Open)
 

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