Thermal processing method for large-diameter refined hot-work die steel forge piece

The invention relates to a thermal processing method for a large-diameter refined hot-work die steel forge piece. The thermal processing method comprises the following steps: cutting off a dead head and staggered ingot tails after heating steel ingots, and axially upsetting the steel ingots; turning over the axially upset blank by 90 degrees, and upsetting the blank on an upper flat plate and a lower platform in a radial direction; turning over the blank which is upset in the radial direction by 90 degrees for erecting, and performing radial upsetting in the other direction on the upper flat plate and the lower platform; drawing the blank on an upper flat anvil and a lower flat anvil in the axial direction to define flat and square blank, and slightly chamfering the blank; erecting the drawn blank for second-time axial upsetting; upsetting the blank which is upset axially on the upper flat plate and the lower platform in the radial direction, wherein the radial direction is width-upsetdimensional direction of