Methodology to Investigate the Transformation Plasticity for Numerical Modelling of Hot Forging Processes

authored by: Bernd Arno Behrens, Kai Brunotte, Hendrik Wester, Christoph Kock
Abstract: Hot forging is a complex process involving the mutual influence of numerous thermo-mechanical-metallurgical material phenomena. In particular, the strains of transformation-induced plasticity (TRIP) have a significant influence on the distortions and residual stresses of the components. The TRIP strains refer to the anisotropic strains depending on the orientation and significance of the stress conditions during cooling superimposed to the phase transformation. With the use of numerical models, the impact of this effect can be investigated in order to ensure the production of high quality components. However, an experimental determination of the characteristic values of TRIP is challenging, which is why only few corresponding data are available in the literature. Therefore, this paper presents an experimental and numerical methodology as well as the results of studies on the interaction between stresses and phase transformations in the materials AISI 4140 and AISI 52100. The investigations of the TRIP strains are carried out using hollow specimens, which are thermo-mechanically treated in the physical forming simulator Gleeble 3800-GTC. The specimens are austenitised, quenched to test temperature and held there while diffusion controlled phase transformation takes place. The extent of TRIP as a result of different superimposed tensile or compressive loads is determined by means of dilatometry. In addition, the extent of TRIP for diffusionless martensitic phase transformations was investigated by continuous cooling tests under tensile and compressive loads. It was found that the transformation plasticity varies depending on the material, the phase type, the temperature and the tensile or compressive stresses. Subsequently, simulations of the physical experiments using the FE software Simufact. Forming verified the determined phase specific values of TRIP.
Organisation(s): Institute of Metal Forming and Metal Forming Machines
Type: Conference contribution
Pages: 547-558
No. of pages: 12
Publication date: 2022
Publication status: Published
Peer reviewed: Yes
ASJC Scopus subject areas: Materials Science(all), Mechanics of Materials, Mechanical Engineering
Electronic version(s): https://doi.org/10.4028/p-51lv37 (Access: Open)
: Details in the research portal "Research@Leibniz University"

BibTeX

@inproceedings{ad7d5163f38c4ecea0bd2cde2b7238bc,
title = "Methodology to Investigate the Transformation Plasticity for Numerical Modelling of Hot Forging Processes",
abstract = "Hot forging is a complex process involving the mutual influence of numerous thermo-mechanical-metallurgical material phenomena. In particular, the strains of transformation-induced plasticity (TRIP) have a significant influence on the distortions and residual stresses of the components. The TRIP strains refer to the anisotropic strains depending on the orientation and significance of the stress conditions during cooling superimposed to the phase transformation. With the use of numerical models, the impact of this effect can be investigated in order to ensure the production of high quality components. However, an experimental determination of the characteristic values of TRIP is challenging, which is why only few corresponding data are available in the literature. Therefore, this paper presents an experimental and numerical methodology as well as the results of studies on the interaction between stresses and phase transformations in the materials AISI 4140 and AISI 52100. The investigations of the TRIP strains are carried out using hollow specimens, which are thermo-mechanically treated in the physical forming simulator Gleeble 3800-GTC. The specimens are austenitised, quenched to test temperature and held there while diffusion controlled phase transformation takes place. The extent of TRIP as a result of different superimposed tensile or compressive loads is determined by means of dilatometry. In addition, the extent of TRIP for diffusionless martensitic phase transformations was investigated by continuous cooling tests under tensile and compressive loads. It was found that the transformation plasticity varies depending on the material, the phase type, the temperature and the tensile or compressive stresses. Subsequently, simulations of the physical experiments using the FE software Simufact. Forming verified the determined phase specific values of TRIP.",
keywords = "AISI 4140, AISI 52100, FE-simulation, Gleeble 3800-GTC, Hot forging, phase transformation, transformation-induced plasticity",
author = "Behrens, {Bernd Arno} and Kai Brunotte and Hendrik Wester and Christoph Kock",
note = "Funding Information: This study was funded by the German Research Foundation (DFG, Deutsche Forschungsgemeinschaft) - 212963651 (BE 1691/142-2) as well as 374871564 (BE 1691/223-2) within the priority program SPP 2013. ; 25th International Conference on Material Forming, ESAFORM 2022 ; Conference date: 27-04-2022 Through 29-04-2022",
year = "2022",
doi = "10.4028/p-51lv37",
language = "English",
isbn = "9783035717594",
series = "Key Engineering Materials",
publisher = "Trans Tech Publications Ltd",
pages = "547--558",
editor = "Gabriela Vincze and Fr{\'e}d{\'e}ric Barlat",
booktitle = "Achievements and Trends in Material Forming- Peer-reviewed extended papers selected from the 25th International Conference on Material Forming, ESAFORM 2022",
}