Hits:

Indexed by:期刊论文

Date of Publication:2008-07-01

Journal:STEEL RESEARCH INTERNATIONAL

Included Journals:SCIE、EI

Volume:79

Issue:7

Page Number:564-568

ISSN No.:1611-3683

Key Words:friction force; non-sinusoidal oscillation; phase lag; amount of negative strip; pressure work

Abstract:Friction force is an important parameter to evaluate powder lubrication and reflect the interaction between mould and strand shell. A non-sinusoidal oscillation pattern emerges under high speed continuous casting, the characteristic of which is that the time of upward motion is longer than that of the downward motion within one cycle. In the present research experiments were performed on a slab continuous caster with a strand size of 1000 mm x120 mm. The friction forces of sinusoidal and non-sinusoidal oscillation under the same parameters were calculated and comparatively analysed. The results show that the friction forces of both oscillation patterns approximately change along with velocity, and present a trend to a trapezoid wave, but there is a phase difference between the friction force and relative velocity. Compared with sinusoidal oscillation, the non-sinusoidal oscillation pattern exhibits some important advantages as follows: the maximal and average compressive forces and the compressive force work acting on the strand shell are all higher, the maximal tension is lower, and the actual amount of negative strip is higher. These advantages effect better healing of surface cracks and strand demoulds, and reduce the generation and expansion of cracks, consequently improve the surface quality.