Heavy warm rolling for the production of thin hot strips
Within this project, the heavy warm rolling route is proposed as an alternative for the production of thin gauge hot strips. The mechanical properties are comparable to those obtained after ferrite rolling on the hot strip mill (HSM). The main benefit of the new process is the reinstatement of the high productivity at the HSM. Soft thin hot strips based on ELC or ULC grades can be obtained as a final product directly after coiling or after an additional annealing treatment. For IF steel, a post-annealing treatment is required to attain recrystallisation. Direct recrystallisation in the coil is only manageable with additional actuators to prevent temperature loss and ensure high deformation and coiling temperatures. The new production route allows, furthermore, the making of improved high carbon (0.15 to O.67wt%) steel grades with globularised pearlite. The effect of deformation, coiling temperature and strain is investigated. The main advantages of steels with ferrite-spheroidised cementite are the essentially higher uniform elongation and reduction of area at the same yield strength compared with ferrite-lamellar pearlite structures. Modelling of rolling forces shows that high reductions in one single stand are quite easily attainable for ULC and IF. For steels with a higher deformation resistance, additional measures must be taken to reduce the rolling force and increase the reduction. The heterogeneous temperature distribution of the strip, mainly induced during coil manipulation, calls for specific solutions like induction heating devices, tunnel furnaces or the use of preheated sleeves. The economic evaluation shows that the production of thin hot strips (0.7 to 2 mm) may be attractive from an investment point of view.
Bibliographic Reference: EUR 21946 EN (2006), 141 pp. Euro: 25
Availability: Katalogue Number: KI-NA- 21946-EN-S The paper version can be ordered online and the PDF version downloaded at: http://bookshop.europa.eu
ISBN: ISBN: 92-79-00613-4
Record Number: 200618656 / Last updated on: 2006-07-18
Original language: en
Available languages: en