| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a damage evaluation method of a cold forging metal mold which can more properly perform the damage evaluation of fatigue, wear or the like in an actual cold forging metal mold than a conventional method.SOLUTION: Forging processing for forming an annular flange 56 by compression-deforming an external peripheral part of a material 18 to be forged at a tip face of a punch 36 in the axial direction is performed by using a damage evaluation die 53 which holds the columnar material 18 to be forged and a damage evaluation punch 36 having a ring-shaped wall part 40 which forms a bottomed recess. At this time, a fatigue test is performed in which the forging processing is repeatedly performed by using a plurality of kinds of shape-different punches which are made to differ in stress load amounts applied on a root region 42 of the wall part 40 being a fatigue evaluation part, a relationship between the stress load amounts and a fatigue life of the root region 42 is acquired, and damage caused by the fatigue of an actual cold forging metal mold is predicted and evaluated.</p> |
