Abstract:The use of a continuous casting process to produce heavy steel plates offers significant advantages in terms of low energy consumption, low carbon emissions and high efficiency. However, due to the central segregation and loose of the slab and the large internal inclusions are not well controlled, it is the main reason for the ultrasonic flaw detection of the thick plate of ≥100 mm thickness. In view of this, the internal inclusion removal technology and center segregation and loose control technology for extrathick slab were developed. The optimum vertical section height of the caster which can fully facilitate the removal of inclusions and the solidification end reduction ratio parameters for the central segregation and loose defects of the slab are given. The application results show that the above quality measures have achieved obvious results, and the quality of the extrathick slabs produced is good.