Production method of high-uniformity pre-hardened plastic die steel

The invention belongs to the technical field of metallurgical material preparation, and particularly relates to a production method of high-uniformity pre-hardened plastic die steel. The process comprises the following steps of converter smelting, LF refining, RH refining, continuous casting, casting blank heating, high-pressure water descaling, two-stage rolling, straightening, off-line stacking and slow cooling for 48 hours, flaw detection, tempering treatment, sampling inspection and warehousing and shipping. The pre-hardened plastic die steel of which the thickness specification is 10-100mm, the Rockwell hardness reaches 31 +/-2HRC and the hardness fluctuation of the same plate is less than or equal to 1HRC is produced through reasonable allocation of the contents of C, Mn, Cr and Mo and reasonable allocation of a reasonable heating schedule, a rolling process, a slow cooling process and a tempering heat treatment process, the product quality is stable and uniform, and the production process is simple and