连铸特厚板坯内部质量控制的关键技术

 采用连铸工艺流程生产特厚钢板具有低能耗、低排放和高效率的显著优势。然而，连铸坯中心偏析与疏松、内部大尺寸夹杂物未能得到较好的控制，是导致厚度不小于100 mm特厚板探伤不合格的主要原因。鉴于此，研发了特厚板连铸坯内部夹杂物去除技术与中心偏析、疏松控制技术，给出了利于夹杂物充分上浮去除的铸机最佳垂直段高度，以及改善铸坯中心偏析与疏松缺陷的凝固末端压下率参数。应用结果表明，上述技术措施取得了明显效果，生产的特厚板坯质量良好，采用连铸特厚板坯轧制出了优质特厚板。

Key technology of internal quality control for#br# continuous casting extra thick slab

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 extra thick 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 extra thick slabs produced is good.