MOLD LIFE PREDICTION METHOD

Provided is a method for predicting the thermal fatigue life of a mold. The method for predicting the thermal fatigue life of a mold made of a mold material having hardness H, in which heating in contact with a workpiece and cooling after the contact with the workpiece are repeated, the method comprising: calculating the temperature distribution of the mold heated through the contact with the workpiece; calculating a thermal stress distribution generated in the mold on the basis of the temperature distribution; calculating, from the thermal stress distribution, a thermal stress maximum value σh_MAXat a position x of the mold and a temperature That the thermal stress maximum value σh_MAX; calculating, by using the mold material having the hardness H, a yield strength σy(Th) at the temperature Thand the contraction ϕ(Tc) at the temperature Tcof the mold when cooled; and calculating a thermal fatigue life N at the position x of the mold by assigning σh_MAX, σy(Th), and ϕ(Tc) to the relational formula:N=C1σyTh/σh_MAXm⋅ln1−φTc−1−C2n(C1, C2, m, and n are constants).