September 07, 2008
Severstal to modernize billet caster at Cherepovets
Severstal has awarded Siemens Metals Technologies a contract for the upgrading of their 6 strand billet caster located at Cherepovets in Russia. Upon completion of this project in early 2008, Severstal will be able to increase their casting speed and thus their total billet production.
This order was received following casting trials where billet speeds exceeding seven meters per minute could be demonstrated on a test strand equipped with a Siemens DynaFlex Oscillator. The remaining five strands will now be installed with this technology.
As part of a test campaign, Siemens replaced the existing electro mechanical mold oscillator with a DynaFlex hydraulic oscillator on one of the strands, adapted the strand containment system and modified the secondary cooling system in order to demonstrate high speed casting operations. The replacement of the electro mechanical oscillator was necessary due to the limitations of this equipment unit at higher casting speeds with respect to increased vibrations and oscillation deviations, in addition to the inability to adjust the oscillation stroke of the unit during operations to satisfy the actual casting requirements. The casting tests were performed on a 100x100 billet and casting speeds in excess of seven meters per minute could be demonstrated more than one meter per minute faster than during normal operations with the existing facility.
On the basis of these successful high speed casting demonstrations, Severstal commissioned Siemens to outfit the remaining five strands of the billet caster with DynaFlex oscillation technology and to modify their secondary-cooling systems to satisfy the requirements for higher-speed casting. Additionally electrical equipment and the Level 1 automation system will be modified.
The DynaFlex oscillation system allows the mold oscillation parameters, such as stroke and oscillation frequency, to be controlled and optimized online according to the actual casting requirements. This leads to improved strand-surface quality and casting operations. As opposed to other systems based on the use of bearings, the leaf-spring guiding system of the DynaFlex oscillator is the basis for virtual wear free performance.
As part of its modernization program to improve the output and quality of steel, a 6 strand continuous billet casting machine was installed in 2002 and a second EAF was subsequently installed in the electric arc shop in Cherepovets. The billet caster produces approximately 1 million tonne of steel per year in 100mm x 100mm and 150mm x 150mm square billets for subsequent rolling into rebars and structural steels for use in the construction industry.
