For a better user experience please update your browser or use Chrome or Firefox browser.
Utilities
Publication detail
HomeCold heading quality low-carbon ultra-high-strength bainitic steels (Coheadbain)
Publication metadata
The chemical composition and wire-rod production process of low-carbon, precipitation-strengthened bainitic steels were specially designed for the production of cold-headed products without heat-treating operations. The chemical composition of the bainitic steel was developed using high Ti content, in the range of 0.1-0.2 %. The experimental steel contained 0.06-0.08 % C, ~ 1.9 % Mn, ~ 0.3 % Ni + Cu, ~ 0.002 % B and ~ 0.1 % Ti. The low-carbon cementite-free granular bainite, in which the precipitation of brittle cementite is replaced by the finely dispersed MX-type carbides and a ductile second phase, is the most suitable microstructure, which fulfils the cold headability requirements. The investigation has shown that the exceptional workability of wire rod, as well as the high strength and ductility of the final products, can be achieved by developing in the wire rod during TMCP either non-recrystallised (pancaked) or, alternatively, dynamically recrystallised austenite grains with an average size of less than 15μm, followed by accelerated cooling at rates in the range 3-6 ° C/s to 500-400 °C. After accelerated cooling, the wire rod is slowly cooled in coil, which allows for intense precipitation of TiC. Industrial trials of wire rod rolling were successfully performed. Industrial trials of cold forging of the rod and wire rod produced from the Ti steel were also conducted. The cold-headed fasteners and machinery components were thoroughly investigated. The trials finished with the production of cold-headed fasteners fulfilling the 8.8 class property requirements without the Q & T treatment.
- Published:
- Corporate author(s): Directorate-General for Research and Innovation (European Commission)
- Personal author(s): Kawalla, R ; Zając, S ; Kuziak, R
- Themes: Industrial research and development , Basic metals industry, steel industry
- Subject: chemical compound , industrial research , iron and steel industry , physical process , quality standard , resistance of materials , steel , testing
|
Paper
|
|||
| ISSN 1018-5593 | ISBN 978-92-79-14229-1 | DOI 10.2777/81813 | Catalogue number KI-NA-24191-EN-C |
- Released on EU publications website:
Document viewer
Note:
The publication cannot be displayed in the document viewer. Open web version
You may access it from: Download and languages