The invention discloses a precise heat treatment and
quenching technology of a precision part of high-purity hot-work die steel, and belongs to the field of special steel heat treatment. The high-purity hot-work die steel ASSAB 8407 material imported from Sweden is aimed, wherein the material mainly comprises the following components of 0.39% of C, 5.2% of Cr, 0.1% of Si, 1.4% of Mo, 0.9% of V, and the precise heat treatment and
quenching technology is provided. In the heat treatment process, different
tempering temperatures are adopted to obtain accurate
hardness; different heat
treatment time is adopted for workpieces with different thicknesses, so that
crystal grain changes inside the material can be accurately controlled, grain refinement can be kept, the structure is uniform, the workpiece of a die can obtain high
impact toughness and
high wear resistance; according to the technical scheme, the method comprises the following steps that (1) the workpiece with the thickness difference smaller than 5 mm is placed into a
quenching furnace, and the workpiece is preheated to 150 DEG C in a heating rate of less than 75 DEG C per hour; (2) two level heating is carried out in the quenching furnace to the quenching temperature of 1020 DEG C and the temperature is kept according to heating preservation time t2; (3) the workpiece is discharged out of the furnace and is air-cooled andquenched; and (4), the workpiece is put into a
tempering furnace two times for
tempering, and tempering temperature T DEG C is carried out according to tempering heat preservation time t3 and t4 (FIG.1).