--- _id: '22930' abstract: - lang: eng text: Self-piercing riveting is an established technique for joining multi-material structures in car body manufacturing. Rivets for self-piercing riveting differ in their geometry, the material used, the condition of the material and their surface condition. To shorten the manufacturing process by omitting the heat treatment and the coating process, the authors have elaborated a concept for the use of stainless steel with high strain hardening as a rivet material. The focus of the present investigation is on the evaluation of the influences of the rivet’s geometry and material on its deformation behaviour. Conventional rivets of types P and HD2, a rivet with an improved geometry made of treatable steel 38B2, and rivets made of the stainless steels 1.3815 and 1.4541 are examined. The analysis is conducted by means of multi-step joining tests for two material combinations comprising high-strength steel HCT70X and aluminium EN AW-5083. The joints are cut to provide a cross-section and the deformation behaviour of the different rivets is analysed on the basis of the measured changes in geometry and hardness. In parallel, an examination of the force-stroke curves provides further insights. It can be demonstrated that, besides the geometry, the material strength, in particular, has a significant influence on the deformation behaviour of the rivet. The strength of steel 1.4541 is seen to be too low for the joining task, while the strength of steel 1.3815 is sufficient, and hence the investigation confirms the capability of rivets made of 1.3815 for joining even challenging material combinations. author: - first_name: Benedikt full_name: Uhe, Benedikt id: '38131' last_name: Uhe - first_name: Clara-Maria full_name: Kuball, Clara-Maria last_name: Kuball - first_name: Marion full_name: Merklein, Marion last_name: Merklein - first_name: Gerson full_name: Meschut, Gerson id: '32056' last_name: Meschut orcid: 0000-0002-2763-1246 citation: ama: 'Uhe B, Kuball C-M, Merklein M, Meschut G. Self-Piercing Riveting Using Rivets Made of Stainless Steel with High Strain Hardening. In: Daehn G, Cao J, Kinsey B, Tekkaya E, Vivek A, Yoshida Y, eds. Forming the Future - Proceedings of the 13th International Conference on the Technology of Plasticity. The Minerals, Metals & Materials Series. Springer; 2021:1495-1506. doi:10.1007/978-3-030-75381-8_124' apa: Uhe, B., Kuball, C.-M., Merklein, M., & Meschut, G. (2021). Self-Piercing Riveting Using Rivets Made of Stainless Steel with High Strain Hardening. In G. Daehn, J. Cao, B. Kinsey, E. Tekkaya, A. Vivek, & Y. Yoshida (Eds.), Forming the Future - Proceedings of the 13th International Conference on the Technology of Plasticity. The Minerals, Metals & Materials Series. (pp. 1495–1506). Springer. https://doi.org/10.1007/978-3-030-75381-8_124 bibtex: '@inbook{Uhe_Kuball_Merklein_Meschut_2021, place={Cham}, title={Self-Piercing Riveting Using Rivets Made of Stainless Steel with High Strain Hardening}, DOI={10.1007/978-3-030-75381-8_124}, booktitle={Forming the Future - Proceedings of the 13th International Conference on the Technology of Plasticity. The Minerals, Metals & Materials Series.}, publisher={Springer}, author={Uhe, Benedikt and Kuball, Clara-Maria and Merklein, Marion and Meschut, Gerson}, editor={Daehn, Glenn and Cao, Jian and Kinsey, Brad and Tekkaya, Erman and Vivek, Anupam and Yoshida, Yoshinori}, year={2021}, pages={1495–1506} }' chicago: 'Uhe, Benedikt, Clara-Maria Kuball, Marion Merklein, and Gerson Meschut. “Self-Piercing Riveting Using Rivets Made of Stainless Steel with High Strain Hardening.” In Forming the Future - Proceedings of the 13th International Conference on the Technology of Plasticity. The Minerals, Metals & Materials Series., edited by Glenn Daehn, Jian Cao, Brad Kinsey, Erman Tekkaya, Anupam Vivek, and Yoshinori Yoshida, 1495–1506. Cham: Springer, 2021. https://doi.org/10.1007/978-3-030-75381-8_124.' ieee: 'B. Uhe, C.-M. Kuball, M. Merklein, and G. Meschut, “Self-Piercing Riveting Using Rivets Made of Stainless Steel with High Strain Hardening,” in Forming the Future - Proceedings of the 13th International Conference on the Technology of Plasticity. The Minerals, Metals & Materials Series., G. Daehn, J. Cao, B. Kinsey, E. Tekkaya, A. Vivek, and Y. Yoshida, Eds. Cham: Springer, 2021, pp. 1495–1506.' mla: Uhe, Benedikt, et al. “Self-Piercing Riveting Using Rivets Made of Stainless Steel with High Strain Hardening.” Forming the Future - Proceedings of the 13th International Conference on the Technology of Plasticity. The Minerals, Metals & Materials Series., edited by Glenn Daehn et al., Springer, 2021, pp. 1495–506, doi:10.1007/978-3-030-75381-8_124. short: 'B. Uhe, C.-M. Kuball, M. Merklein, G. Meschut, in: G. Daehn, J. Cao, B. Kinsey, E. Tekkaya, A. Vivek, Y. Yoshida (Eds.), Forming the Future - Proceedings of the 13th International Conference on the Technology of Plasticity. The Minerals, Metals & Materials Series., Springer, Cham, 2021, pp. 1495–1506.' date_created: 2021-08-04T14:02:32Z date_updated: 2023-04-28T09:20:35Z department: - _id: '157' doi: 10.1007/978-3-030-75381-8_124 editor: - first_name: Glenn full_name: Daehn, Glenn last_name: Daehn - first_name: Jian full_name: Cao, Jian last_name: Cao - first_name: Brad full_name: Kinsey, Brad last_name: Kinsey - first_name: Erman full_name: Tekkaya, Erman last_name: Tekkaya - first_name: Anupam full_name: Vivek, Anupam last_name: Vivek - first_name: Yoshinori full_name: Yoshida, Yoshinori last_name: Yoshida keyword: - Self-piercing riveting - Lightweight design - Deformation behaviour - Stainless steel - High nitrogen steel language: - iso: eng page: 1495-1506 place: Cham publication: Forming the Future - Proceedings of the 13th International Conference on the Technology of Plasticity. The Minerals, Metals & Materials Series. publication_status: published publisher: Springer quality_controlled: '1' status: public title: Self-Piercing Riveting Using Rivets Made of Stainless Steel with High Strain Hardening type: book_chapter user_id: '38131' year: '2021' ... --- _id: '22274' abstract: - lang: eng text: 'The use of high-strength steel and aluminium is rising due to the intensified efforts being made in lightweight design, and self-piercing riveting is becoming increasingly important. Conventional rivets for self-piercing riveting differ in their geometry, the material used, the condition of the material and the coating. To shorten the manufacturing process, the use of stainless steel with high strain hardening as the rivet material represents a promising approach. This allows the coating of the rivets to be omitted due to the corrosion resistance of the material and, since the strength of the stainless steel is achieved by cold forming, heat treatment is no longer required. In addition, it is possible to adjust the local strength within the rivet. Because of that, the authors have elaborated a concept for using high nitrogen steel 1.3815 as the rivet material. The present investigation focusses on the joint strength in order to evaluate the capability of rivets in high nitrogen steel by comparison to conventional rivets made of treatable steel. Due to certain challenges in the forming process of the high nitrogen steel rivets, deviations result from the targeted rivet geometry. Mainly these deviations cause a lower joint strength with these rivets, which is, however, adequate. All in all, the capability of the new rivet is proven by the results of this investigation. ' author: - first_name: Benedikt full_name: Uhe, Benedikt id: '38131' last_name: Uhe - first_name: Clara-Maria full_name: Kuball, Clara-Maria last_name: Kuball - first_name: Marion full_name: Merklein, Marion last_name: Merklein - first_name: Gerson full_name: Meschut, Gerson id: '32056' last_name: Meschut orcid: 0000-0002-2763-1246 citation: ama: 'Uhe B, Kuball C-M, Merklein M, Meschut G. Strength of self-piercing riveted Joints with conventional Rivets and Rivets made of High Nitrogen Steel. In: ; 2021. doi:10.25518/esaform21.1911' apa: Uhe, B., Kuball, C.-M., Merklein, M., & Meschut, G. (2021). Strength of self-piercing riveted Joints with conventional Rivets and Rivets made of High Nitrogen Steel. 24th International Conference on Material Forming (ESAFORM), Liège, Belgien. https://doi.org/10.25518/esaform21.1911 bibtex: '@inproceedings{Uhe_Kuball_Merklein_Meschut_2021, title={Strength of self-piercing riveted Joints with conventional Rivets and Rivets made of High Nitrogen Steel}, DOI={10.25518/esaform21.1911}, author={Uhe, Benedikt and Kuball, Clara-Maria and Merklein, Marion and Meschut, Gerson}, year={2021} }' chicago: Uhe, Benedikt, Clara-Maria Kuball, Marion Merklein, and Gerson Meschut. “Strength of Self-Piercing Riveted Joints with Conventional Rivets and Rivets Made of High Nitrogen Steel,” 2021. https://doi.org/10.25518/esaform21.1911. ieee: 'B. Uhe, C.-M. Kuball, M. Merklein, and G. Meschut, “Strength of self-piercing riveted Joints with conventional Rivets and Rivets made of High Nitrogen Steel,” presented at the 24th International Conference on Material Forming (ESAFORM), Liège, Belgien, 2021, doi: 10.25518/esaform21.1911.' mla: Uhe, Benedikt, et al. Strength of Self-Piercing Riveted Joints with Conventional Rivets and Rivets Made of High Nitrogen Steel. 2021, doi:10.25518/esaform21.1911. short: 'B. Uhe, C.-M. Kuball, M. Merklein, G. Meschut, in: 2021.' conference: end_date: 2021-04-16 location: Liège, Belgien name: 24th International Conference on Material Forming (ESAFORM) start_date: 2021-04-14 date_created: 2021-05-31T10:17:37Z date_updated: 2023-04-28T09:20:05Z department: - _id: '157' doi: 10.25518/esaform21.1911 keyword: - Self-piercing Riveting - Joining Technology - Rivet Geometry - Rivet Material - High Nitrogen Steel - Joint Strength language: - iso: eng quality_controlled: '1' status: public title: Strength of self-piercing riveted Joints with conventional Rivets and Rivets made of High Nitrogen Steel type: conference user_id: '38131' year: '2021' ... --- _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' ...