Preparation method of plastic die steel continuous casting slab

The invention discloses a preparation method of a plastic die steel continuous casting sheet billet, and relates to the technical field of steel smelting, the method comprises the following steps: continuously casting molten steel to prepare a continuous casting sheet billet; the pressing mode in the continuous casting process is composed of soft pressing and convex roller large pressing. According to the method, the internal quality of the extra-thick plate blank is improved by adopting a convex roller large reduction technology, and the defects of center segregation and center porosity of the extra-thick plate blank are overcome; the internal quality of the low-compression-ratio flaw-detection-guaranteed extra-thick plate is effectively improved, and the flaw detection qualification rate of the low-compression-ratio flaw-detection-guaranteed extra-thick plate is controlled to be 96% or above. The ultra-thick plate blank industrially produced through the method is good in effect after implementation, and the