The invention discloses a production technology of a non-modulated plastic die steel
thick plate. The production technology comprises the following steps: converter
smelting and
ladle furnace (LF) and Ruhrstahl Heraeus (RH) refining are adopted to pour a continuous cast billet; the
heating temperature is 1150-1200 DEG C, the precision rolling temperature is 900-950 DEG C, the finish rolling temperature is 860-900 DEG C; the cooling control of the steel plate is performed after the steel plate is rolled, the phase transformation strengthening and the
precipitation strengthening of the microalloyed
carbon nitride are utilized to ensure that when the section of the steel plate is not modulated, the structure and performance are uniform along the section, the plastic die steel of which section
hardness is 300-340 is obtained; the rolled steel plate is tempered to eliminate the stress and avoid sawing crack, the
hardness of the steel plate is uniform after
tempering, and the section has granular
bainite structure. In the production technology, the
alloy component is controlled, Ni is not added, a small amount of Mo, B and V are added and the Cr content is increased properly, thus the steel plate has higher
hardenability; and the cooling control of the rolled steel plate is performed to ensure that the large-section steel plate has
bainite structure. The production technology is suitable for the production of the non-modulated plastic die steel
thick plate, which is prepared from the 320mm continuous cast billet and of which thickness is less than 120mm.