Resistance Heating by Means of Direct Current for Resource-Saving CO2-Neutral Hot Stamping

authored by: Bernd Arno Behrens, Sven Hübner, Lorenz Albracht, Ehsan Farahmand
Abstract: Hot stamping is a well-established and frequently used manufacturing process in automotive body construction. The number of components manufactured in this way is continuously increasing. Hot stamping is used to produce components with a completely martensitic structure, resulting in high strength and hardness. These components are mainly used in safety-relevant areas of the passenger cell, such as the A-pillar, B-pillar, tunnel and sill. For hot-stamping processes, it is necessary to austenitize the blanks. Heating the sheet metal up to 930 °C in a furnace is very energy-intensive. In large-scale industrial applications, the sheets are generally heated in gas-fired roller hearth furnaces up to 60 m long. Apart from the poor energy balance and the high CO2 emissions of such furnaces, they are associated with high investment and maintenance costs, large space requirements and a long heating time. Rapid heating by means of the Joule effect and direct current instead of alternating current offer an energy-efficient and environmentally friendly alternative for sheet metal heating. Therefore, this technology can make a major contribution to environmental protection and resource saving. Within the scope of this work, parts were rapid-heated and subsequently hot-stamped by means of a novel heating system based on direct current with energy savings of up to 80 %. Using electricity guarantees a good CO2 balance. In addition, resistance heating with a new type of DC-heating system and an adapted process chain is compared with conventional furnace heating. In thermographic images and microstructural examinations of the hot-stamped parts, it can be demonstrated that this direct-current technique is well suited for achieving homogeneous hardness and strength in the whole sheet metal. Thus, this new heating system can enhance the efficiency of the hot-stamping technology.
Organisation(s): Institute of Metal Forming and Metal Forming Machines
Type: Conference contribution
Pages: 2363-2370
No. of pages: 8
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-99k4fg (Access: Open)
: Details in the research portal "Research@Leibniz University"

BibTeX

@inproceedings{12eade1b0fa44d3ebb064602511b3ce6,
title = "Resistance Heating by Means of Direct Current for Resource-Saving CO2-Neutral Hot Stamping",
abstract = "Hot stamping is a well-established and frequently used manufacturing process in automotive body construction. The number of components manufactured in this way is continuously increasing. Hot stamping is used to produce components with a completely martensitic structure, resulting in high strength and hardness. These components are mainly used in safety-relevant areas of the passenger cell, such as the A-pillar, B-pillar, tunnel and sill. For hot-stamping processes, it is necessary to austenitize the blanks. Heating the sheet metal up to 930 °C in a furnace is very energy-intensive. In large-scale industrial applications, the sheets are generally heated in gas-fired roller hearth furnaces up to 60 m long. Apart from the poor energy balance and the high CO2 emissions of such furnaces, they are associated with high investment and maintenance costs, large space requirements and a long heating time. Rapid heating by means of the Joule effect and direct current instead of alternating current offer an energy-efficient and environmentally friendly alternative for sheet metal heating. Therefore, this technology can make a major contribution to environmental protection and resource saving. Within the scope of this work, parts were rapid-heated and subsequently hot-stamped by means of a novel heating system based on direct current with energy savings of up to 80 %. Using electricity guarantees a good CO2 balance. In addition, resistance heating with a new type of DC-heating system and an adapted process chain is compared with conventional furnace heating. In thermographic images and microstructural examinations of the hot-stamped parts, it can be demonstrated that this direct-current technique is well suited for achieving homogeneous hardness and strength in the whole sheet metal. Thus, this new heating system can enhance the efficiency of the hot-stamping technology.",
keywords = "CO neutral heating, DC resistance heating, energy saving, hot stamping",
author = "Behrens, {Bernd Arno} and Sven H{\"u}bner and Lorenz Albracht and Ehsan Farahmand",
year = "2022",
doi = "10.4028/p-99k4fg",
language = "English",
isbn = "9783035717594",
series = "Key Engineering Materials",
publisher = "Trans Tech Publications Ltd",
pages = "2363--2370",
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",
note = "25th International Conference on Material Forming, ESAFORM 2022 ; Conference date: 27-04-2022 Through 29-04-2022",
}