Influence of the process temperature on the forming behaviour and the friction during bulk forming of high nitrogen steel
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...
| Main Authors: | , , , , |
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| Format: | Article |
| Language: | English |
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Elsevier
2020-03-01
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| Series: | Journal of Advanced Joining Processes |
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| Online Access: | http://www.sciencedirect.com/science/article/pii/S2666330920300212 |
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| author | C.-M. Kuball R. Jung B. Uhe G. Meschut M. Merklein |
| author_facet | C.-M. Kuball R. Jung B. Uhe G. Meschut M. Merklein |
| author_sort | C.-M. Kuball |
| collection | DOAJ |
| description | 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. |
| first_indexed | 2024-12-16T11:40:55Z |
| format | Article |
| id | doaj.art-0b7fbe91fea749c18edaaf9335f70eb9 |
| institution | Directory Open Access Journal |
| issn | 2666-3309 |
| language | English |
| last_indexed | 2024-12-16T11:40:55Z |
| publishDate | 2020-03-01 |
| publisher | Elsevier |
| record_format | Article |
| series | Journal of Advanced Joining Processes |
| spelling | doaj.art-0b7fbe91fea749c18edaaf9335f70eb92022-12-21T22:32:56ZengElsevierJournal of Advanced Joining Processes2666-33092020-03-011100023Influence of the process temperature on the forming behaviour and the friction during bulk forming of high nitrogen steelC.-M. Kuball0R. Jung1B. Uhe2G. Meschut3M. Merklein4Friedrich-Alexander-Universität Erlangen-Nürnberg, Institute of Manufacturing Technology (LFT), Egerlandstraße 13, 91058 Erlangen, Germany; Corresponding author.Friedrich-Alexander-Universität Erlangen-Nürnberg, Institute of Manufacturing Technology (LFT), Egerlandstraße 13, 91058 Erlangen, GermanyPaderborn University, Laboratory for Material and Joining Technology (LWF), Pohlweg 47-49, 33098 Paderborn, GermanyPaderborn University, Laboratory for Material and Joining Technology (LWF), Pohlweg 47-49, 33098 Paderborn, GermanyFriedrich-Alexander-Universität Erlangen-Nürnberg, Institute of Manufacturing Technology (LFT), Egerlandstraße 13, 91058 Erlangen, GermanyDue 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.http://www.sciencedirect.com/science/article/pii/S2666330920300212High nitrogen steelSelf-piercing rivetingJoining by formingBulk formingStrain hardening |
| spellingShingle | C.-M. Kuball R. Jung B. Uhe G. Meschut M. Merklein Influence of the process temperature on the forming behaviour and the friction during bulk forming of high nitrogen steel Journal of Advanced Joining Processes High nitrogen steel Self-piercing riveting Joining by forming Bulk forming Strain hardening |
| title | Influence of the process temperature on the forming behaviour and the friction during bulk forming of high nitrogen steel |
| title_full | Influence of the process temperature on the forming behaviour and the friction during bulk forming of high nitrogen steel |
| title_fullStr | Influence of the process temperature on the forming behaviour and the friction during bulk forming of high nitrogen steel |
| title_full_unstemmed | Influence of the process temperature on the forming behaviour and the friction during bulk forming of high nitrogen steel |
| title_short | Influence of the process temperature on the forming behaviour and the friction during bulk forming of high nitrogen steel |
| title_sort | influence of the process temperature on the forming behaviour and the friction during bulk forming of high nitrogen steel |
| topic | High nitrogen steel Self-piercing riveting Joining by forming Bulk forming Strain hardening |
| url | http://www.sciencedirect.com/science/article/pii/S2666330920300212 |
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