Details
| Original language | English |
|---|---|
| Pages (from-to) | 1345-1352 |
| Number of pages | 8 |
| Journal | Procedia Manufacturing |
| Volume | 47 |
| Publication status | Published - 26 Apr 2020 |
| Event | 23rd International Conference on Material Forming, ESAFORM 2020 - Cottbus, Germany Duration: 4 May 2020 → … |
Abstract
Press hardened structural components are a key factor in lightweight car design and thus in reducing vehicle mass while increasing crash safety. The use of quenched 22MnB5 (Usibor 1500) has been established in hot sheet forming for the production of safety-relevant car body components. In order to expand the field of application for press-hardened components, a process-reliable joining technique is essential. Ultrahigh-strength components can be joined with other parts in car bodies using the resistance spot welding process. Here, challenges like uneven welding lens formations with an incorrect connection in multi-sheet joints arise. Mechanical joining processes, for example self-pierce riveting, can only be used to a limited extent due to the high hardness of the hardened parts. For this purpose, an annealing treatment is often carried out in order to reduce the strength of the material after press hardening. Another possibility to create softened areas is the introduction of local deformation in the austenitic material. The phase areas in the continuous cooling transformation diagram are shifted to shorter cooling times, which enables the development of deformation-induced ferrite. The local thinning and softening improves joinability by means of mechanical and thermal joining processes but increases the forming force. Therefore, in this study the process of hot forming and local deformation is first pre-estimated using numerical simulation. The required force for the deformation and an optimal positioning, as well as the possible number of deformation punches, are investigated. Furthermore, the first experimental results of the feasibility of locally thinned and softened sheets are presented. In addition, joining tests by resistance spot welding and self-pierce riveting are carried out on the generated specimen to illustrate the practical effectiveness of the local thinning and the use of deformation-induced ferrite for critical joints.
Keywords
- Deformation-induced ferrite, FE-simulation, Press hardening, Resistance spot welding, Self-pierce riveting
ASJC Scopus subject areas
- Engineering(all)
- Industrial and Manufacturing Engineering
- Computer Science(all)
- Artificial Intelligence
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In: Procedia Manufacturing, Vol. 47, 26.04.2020, p. 1345-1352.
Research output: Contribution to journal › Conference article › Research › peer review
}
TY - JOUR
T1 - Extension of the Conventional Press Hardening Process by Local Material Influence to Improve Joining Ability
AU - Behrens, Bernd Arno
AU - Jüttner, Sven
AU - Brunotte, Kai
AU - Özkaya, Fahrettin
AU - Wohner, Maximilian
AU - Stockburger, Eugen
N1 - Funding Information: The authors gratefully acknowledge the financial support of the Research Association for Steel Application (FOSTA) and the German Federation of Industrial Research Associations (AiF) for this research work (AiF Ref.-No. 19797 BG). Furthermore, the authors would like to thank the industrial partners in this research project for the scientific exchange and discussion. Funding Information: A.L.M. Costa acknowledge Brazilian National Council for Development – CNPq.
PY - 2020/4/26
Y1 - 2020/4/26
N2 - Press hardened structural components are a key factor in lightweight car design and thus in reducing vehicle mass while increasing crash safety. The use of quenched 22MnB5 (Usibor 1500) has been established in hot sheet forming for the production of safety-relevant car body components. In order to expand the field of application for press-hardened components, a process-reliable joining technique is essential. Ultrahigh-strength components can be joined with other parts in car bodies using the resistance spot welding process. Here, challenges like uneven welding lens formations with an incorrect connection in multi-sheet joints arise. Mechanical joining processes, for example self-pierce riveting, can only be used to a limited extent due to the high hardness of the hardened parts. For this purpose, an annealing treatment is often carried out in order to reduce the strength of the material after press hardening. Another possibility to create softened areas is the introduction of local deformation in the austenitic material. The phase areas in the continuous cooling transformation diagram are shifted to shorter cooling times, which enables the development of deformation-induced ferrite. The local thinning and softening improves joinability by means of mechanical and thermal joining processes but increases the forming force. Therefore, in this study the process of hot forming and local deformation is first pre-estimated using numerical simulation. The required force for the deformation and an optimal positioning, as well as the possible number of deformation punches, are investigated. Furthermore, the first experimental results of the feasibility of locally thinned and softened sheets are presented. In addition, joining tests by resistance spot welding and self-pierce riveting are carried out on the generated specimen to illustrate the practical effectiveness of the local thinning and the use of deformation-induced ferrite for critical joints.
AB - Press hardened structural components are a key factor in lightweight car design and thus in reducing vehicle mass while increasing crash safety. The use of quenched 22MnB5 (Usibor 1500) has been established in hot sheet forming for the production of safety-relevant car body components. In order to expand the field of application for press-hardened components, a process-reliable joining technique is essential. Ultrahigh-strength components can be joined with other parts in car bodies using the resistance spot welding process. Here, challenges like uneven welding lens formations with an incorrect connection in multi-sheet joints arise. Mechanical joining processes, for example self-pierce riveting, can only be used to a limited extent due to the high hardness of the hardened parts. For this purpose, an annealing treatment is often carried out in order to reduce the strength of the material after press hardening. Another possibility to create softened areas is the introduction of local deformation in the austenitic material. The phase areas in the continuous cooling transformation diagram are shifted to shorter cooling times, which enables the development of deformation-induced ferrite. The local thinning and softening improves joinability by means of mechanical and thermal joining processes but increases the forming force. Therefore, in this study the process of hot forming and local deformation is first pre-estimated using numerical simulation. The required force for the deformation and an optimal positioning, as well as the possible number of deformation punches, are investigated. Furthermore, the first experimental results of the feasibility of locally thinned and softened sheets are presented. In addition, joining tests by resistance spot welding and self-pierce riveting are carried out on the generated specimen to illustrate the practical effectiveness of the local thinning and the use of deformation-induced ferrite for critical joints.
KW - Deformation-induced ferrite
KW - FE-simulation
KW - Press hardening
KW - Resistance spot welding
KW - Self-pierce riveting
UR - http://www.scopus.com/inward/record.url?scp=85085473375&partnerID=8YFLogxK
U2 - 10.1016/j.promfg.2020.04.258
DO - 10.1016/j.promfg.2020.04.258
M3 - Conference article
AN - SCOPUS:85085473375
VL - 47
SP - 1345
EP - 1352
JO - Procedia Manufacturing
JF - Procedia Manufacturing
SN - 2351-9789
T2 - 23rd International Conference on Material Forming, ESAFORM 2020
Y2 - 4 May 2020
ER -