PHYSICAL SIMULATION OF CONTROLLED ROLLING AND COOLING OF NB-TI MICROALLOYED STEEL STRIP

1 LATOCHA Mario
Co-authors:
1 ŠEVČÁK Vojtěch 1 SCHINDLER Ivo 1 OPĚLA Petr 1 KAWULOK Petr 2 JUHÁR Ľuboš
Institutions:
1 VŠB – Technical University of Ostrava, Faculty of Metallurgy and Materials Engineering, 17.listopadu 15, 708 33 Ostrava, Czech Republic, ivo.schindler@vsb.cz
2 U. S. Steel Košice, s.r.o. 044 54 Košice, Slovakia
Conference:
27th International Conference on Metallurgy and Materials, Hotel Voronez I, Brno, Czech Republic, EU, May 23rd - 25th 2018
Proceedings:
Proceedings 27th International Conference on Metallurgy and Materials
Pages:
482-486
ISBN:
978-80-87294-84-0
ISSN:
2694-9296
Published:
24th October 2018
Proceedings of the conference were published in Web of Science and Scopus.
Metrics:
22 views / 5 downloads
Abstract

Reversible two-stand two-high laboratory mill TANDEM was used to study the effect of simulation parameters on the final properties of HSLA steel strip with 0.08 % C, 1.26 % Mn, 0.05 % Ti and 0.03 % Nb. The flat samples were heated at 1230 °C for 20 or 60 minutes and rolled from thickness of 24.0 mm to 3.2 mm by 6 passes. After finishing at approx. 868 °C, three different regimes of cooling were applied: free air cooling only, accelerated water cooling down to 560 °C followed by 1-hour stay in furnace at this temperature (simulating the conditions in industrial strip coil), or water spray cooling followed by free air cooling to room temperature. Ductility of the laboratory rolled products was almost constant. Yield stress and strength was only little influenced by simulation complexity after accelerated cooling, but these values were much lower after simple free air cooling (minus 80 MPa in average). After free air cooling, final equiaxed ferrite grain size was rather greater in the case of longer heating (5.2 vs 4.5 µm), but the microstructure was quite different after accelerated cooling when acicular ferrite occurs and pearlite disappears. The obtained results are important from the point of view of the physical simulation methodology.

Keywords: Tandem, cooling mode, HSLA steel
Scroll to Top