(Session6A) THE IMPROVEMENT OF SLAB SURFACE QUALITY BY INSTALLING NEW WATER COOLING SYSTEM AT SLAB CONTINUOUS CASTERS PT. KRAKATAU STEEL (PERSERO) Tbk

摘要

PTKS has been succesfully revitalized its Continuous Casting Machines (CCMs) resulting in an improvement in many aspect such as product quality and machine reliability. The main scope of works consist of installation of new level control system (LevCon) and new water cooling system (Dynacs). The revamping is also carried out on ladle turrets, tundish cars and torch cutting machines as well as replacing DC motors to AC. A significant improvement is achieved not only on the internal quality but also on surface quality.By installation of dynamic cooling at secondary cooling system with 'centre-margin' cooling methode, we can promote good strand cooling especially in the corner of the strand resulting in surface quality improvement as shown during start up i.e 98% free of corner cracks (class 0 up to class 1), 99% free of transversal cracks, 100% free of star cracks, etc. This paper will focus on the improvement of slab corner cracks.