| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for predicting a thermal fatigue life of a die based on a material characteristic and a thermal stress load of a die. SOLUTION: In this method, temperature distribution of a heated die is obtained by contacting with a workpiece, and thermal stress distribution generated to the die is obtained from the temperature distribution. A thermal fatigue life at a given position x of the die is predicted from temperature Th in the heating time at the given position x of the die, thermal stressσn and proof stressσy(Th) at the temperature Th of the die material, and a drawingϕ(Tc) at the temperature Tc during cooling. Preferably, a relation formula of the die thermal fatigue life N, Th,σn,σy (Th), andϕ(Tc) will satisfy N= C1(σy(Th)/σn)m.1n(1-ϕ(Tc))-1-C2}n, where C1, C2, m, n are constants. Further preferably, the temperature distribution and the thermal stress distribution are obtained by a finite element method.
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