---
_id: '19976'
abstract:
- lang: eng
text: The aim to reduce pollutant emission has led to a trend towards lightweight
construction in car body development during the last years. As a consequence of
the resulting need for multi-material design, mechanical joining technologies
become increasingly important. Mechanical joining allows for the combination of
dissimilar materials, while thermic joining techniques reach their limits. Self-piercing
riveting enables the joining of dissimilar materials by using semi-tubular rivets
as mechanical fasteners. The rivet production, however, is costly and time-consuming,
as the rivets generally have to be hardened, tempered and coated after forming,
in order to achieve an adequate strength and corrosion resistance. A promising
approach to improve the efficiency of the rivet manufacturing is the use of high-strength
high nitrogen steel as rivet material because these additional process steps would
not be necessary anymore. As a result of the comparatively high nitrogen content,
such steels have various beneficial properties like higher strength, good ductility
and improved corrosion resistance. By cold bulk forming of high nitrogen steels
high-strength parts can be manufactured due to the strengthening which is caused
by the high strain hardening. However, high tool loads thereby have to be expected
and are a major challenge during the production process. Consequently, there is
a need for appropriate forming strategies. This paper presents key aspects concerning
the process design for the manufacturing of semi-tubular self-piercing rivets
made of high-strength steel. The aim is to produce the rivets in several forming
stages without intermediate heat treatment between the single stages. Due to the
high strain hardening of the material, a two stage forming concept will be investigated.
Cup-backward extrusion is chosen as the first process step in order to form the
rivet shank without forming the rivet foot. Thus, the strain hardening effects
in the area of the rivet foot are minimized and the tool loads during the following
process step can be reduced. During the second and final forming stage the detailed
geometry of the rivet foot and the rivet head is formed. In this context, the
effect of different variations, for example concerning the final geometry of the
rivet foot, on the tool load is investigated using multistage numerical analysis.
Furthermore, the influence of the process temperature on occurring stresses is
analysed. Based on the results of the investigations, an adequate forming strategy
and a tool concept for the manufacturing of semi-tubular self-piercing rivets
made of high-strength steel are presented.
citation:
ama: Kuball C-M, Uhe B, Meschut G, Merklein M, eds. Process Design for the Forming
of Semi-Tubular Self-Piercing Rivets Made of High Nitrogen Steel. Vol 50.;
2020:280-285. doi:10.1016/j.promfg.2020.08.052
apa: Kuball, C.-M., Uhe, B., Meschut, G., & Merklein, M. (Eds.). (2020). Process
design for the forming of semi-tubular self-piercing rivets made of high nitrogen
steel (Vol. 50, pp. 280–285). https://doi.org/10.1016/j.promfg.2020.08.052
bibtex: '@book{Kuball_Uhe_Meschut_Merklein_2020, series={Procedia Manufacturing},
title={Process design for the forming of semi-tubular self-piercing rivets made
of high nitrogen steel}, volume={50}, DOI={10.1016/j.promfg.2020.08.052},
year={2020}, pages={280–285}, collection={Procedia Manufacturing} }'
chicago: Kuball, Clara-Maria, Benedikt Uhe, Gerson Meschut, and Marion Merklein,
eds. Process Design for the Forming of Semi-Tubular Self-Piercing Rivets Made
of High Nitrogen Steel. Vol. 50. Procedia Manufacturing, 2020. https://doi.org/10.1016/j.promfg.2020.08.052.
ieee: C.-M. Kuball, B. Uhe, G. Meschut, and M. Merklein, Eds., Process design
for the forming of semi-tubular self-piercing rivets made of high nitrogen steel,
vol. 50. 2020, pp. 280–285.
mla: Kuball, Clara-Maria, et al., editors. Process Design for the Forming of
Semi-Tubular Self-Piercing Rivets Made of High Nitrogen Steel. Vol. 50, 2020,
pp. 280–85, doi:10.1016/j.promfg.2020.08.052.
short: C.-M. Kuball, B. Uhe, G. Meschut, M. Merklein, eds., Process Design for the
Forming of Semi-Tubular Self-Piercing Rivets Made of High Nitrogen Steel, 2020.
date_created: 2020-10-12T08:30:08Z
date_updated: 2022-01-06T06:54:17Z
department:
- _id: '157'
doi: 10.1016/j.promfg.2020.08.052
editor:
- first_name: Clara-Maria
full_name: Kuball, Clara-Maria
last_name: Kuball
- first_name: Benedikt
full_name: Uhe, Benedikt
id: '38131'
last_name: Uhe
- first_name: Gerson
full_name: Meschut, Gerson
id: '32056'
last_name: Meschut
orcid: 0000-0002-2763-1246
- first_name: Marion
full_name: Merklein, Marion
last_name: Merklein
intvolume: ' 50'
keyword:
- high nitrogen steel
- self-piercing riveting
- joining by forming
- bulk forming
- tool design
language:
- iso: eng
page: 280-285
publication_status: published
quality_controlled: '1'
series_title: Procedia Manufacturing
status: public
title: Process design for the forming of semi-tubular self-piercing rivets made of
high nitrogen steel
type: conference_editor
user_id: '38131'
volume: 50
year: '2020'
...
---
_id: '19974'
abstract:
- lang: eng
text: Due to the trend towards lightweight design in car body development mechanical
joining technologies become increasingly important. These techniques allow for
the joining of dissimilar materials and thus enable multi-material design, while
thermic joining methods reach their limits. Semi-tubular self-piercing riveting
is an important mechanical joining technology. The rivet production, however,
is costly and time-consuming, as the process consists of several process steps
including the heat treatment and coating of the rivets in order to achieve an
adequate strength and corrosion resistance. The use of high nitrogen steel as
rivet material leads to the possibility of reducing process steps and hence increasing
the efficiency of the process. However, the high tool loads being expected due
to the high strain hardening of the material are a major challenge during the
rivet production. Thus, there is a need for appropriate forming strategies, such
as the manufacturing of the rivets at elevated temperatures. Prior investigations
led to the conclusion that forming already at 200 °C results in a distinct reduction
of the yield strength. To create a deeper understanding of the forming behaviour
of high nitrogen steel at elevated temperatures, compression tests were conducted
in a temperature range between room temperature and 200 °C. The determined true
stress – true strain curves are the basis for the further process and tool design
of the rivet production. Another key factor for the rivet manufacturing at elevated
temperatures is the influence of the process temperature on the tribological conditions.
For this reason, ring compression tests at room temperature and 200 °C are carried
out. The friction factors are determined on the basis of calibration curves resulting
from the numerical analysis of the ring compression process. The investigations
indicate that the friction factor at 200 °C is significantly higher compared to
room temperature. This essential fact has to be taken into account for the process
and tool design for the rivet production using high nitrogen steel.
article_number: '100023'
citation:
ama: Kuball C-M, Jung R, Uhe B, Meschut G, Merklein M, eds. Influence of the
Process Temperature on the Forming Behaviour and the Friction during Bulk Forming
of High Nitrogen Steel. Vol 1.; 2020. doi:10.1016/j.jajp.2020.100023
apa: Kuball, C.-M., Jung, R., Uhe, B., Meschut, G., & Merklein, M. (Eds.). (2020).
Influence of the process temperature on the forming behaviour and the friction
during bulk forming of high nitrogen steel (No. 100023; Vol. 1). https://doi.org/10.1016/j.jajp.2020.100023
bibtex: '@book{Kuball_Jung_Uhe_Meschut_Merklein_2020, series={Journal of Advanced
Joining Processes}, title={Influence of the process temperature on the forming
behaviour and the friction during bulk forming of high nitrogen steel}, volume={1},
DOI={10.1016/j.jajp.2020.100023},
number={100023}, year={2020}, collection={Journal of Advanced Joining Processes}
}'
chicago: Kuball, Clara-Maria, R Jung, Benedikt Uhe, Gerson Meschut, and Marion Merklein,
eds. Influence of the Process Temperature on the Forming Behaviour and the
Friction during Bulk Forming of High Nitrogen Steel. Vol. 1. Journal of Advanced
Joining Processes, 2020. https://doi.org/10.1016/j.jajp.2020.100023.
ieee: C.-M. Kuball, R. Jung, B. Uhe, G. Meschut, and M. Merklein, Eds., Influence
of the process temperature on the forming behaviour and the friction during bulk
forming of high nitrogen steel, vol. 1. 2020.
mla: Kuball, Clara-Maria, et al., editors. Influence of the Process Temperature
on the Forming Behaviour and the Friction during Bulk Forming of High Nitrogen
Steel. 100023, 2020, doi:10.1016/j.jajp.2020.100023.
short: C.-M. Kuball, R. Jung, B. Uhe, G. Meschut, M. Merklein, eds., Influence of
the Process Temperature on the Forming Behaviour and the Friction during Bulk
Forming of High Nitrogen Steel, 2020.
date_created: 2020-10-12T08:23:27Z
date_updated: 2023-04-28T09:19:41Z
department:
- _id: '157'
doi: 10.1016/j.jajp.2020.100023
editor:
- first_name: Clara-Maria
full_name: Kuball, Clara-Maria
last_name: Kuball
- first_name: R
full_name: Jung, R
last_name: Jung
- first_name: Benedikt
full_name: Uhe, Benedikt
id: '38131'
last_name: Uhe
- first_name: Gerson
full_name: Meschut, Gerson
id: '32056'
last_name: Meschut
orcid: 0000-0002-2763-1246
- first_name: Marion
full_name: Merklein, Marion
last_name: Merklein
intvolume: ' 1'
keyword:
- High nitrogen steel
- Self-piercing riveting
- Joining by forming
- Bulk forming
- Strain hardening
language:
- iso: eng
publication_status: published
quality_controlled: '1'
series_title: Journal of Advanced Joining Processes
status: public
title: Influence of the process temperature on the forming behaviour and the friction
during bulk forming of high nitrogen steel
type: conference_editor
user_id: '38131'
volume: 1
year: '2020'
...