Study on the Influences of Types of Tool Steel on Wear Behavior of Blanking Die

Abstract

The objective of this research is to study influences of tool materials on wear behavior in theblanking die. Four punch materials: JIS SKD11, SKS3, SKH51 and S50C were studied. Those punchesare hardened to the same hardness of 59 ± 1 HRC. Clearance between punch and die is 5% ofworkpiece thickness. JIS G3141 SPCC steel strip with thickness 0.8 mm is used as workpiecematerial. The strip is blanked into circular shapes of 25 mm in diameter. Each punch was used forblanking 10,000 workpieces. From the experiments, SKD11 has the lowest wear rate. The highercarbon content increases the amount of carbide compounds, which are very much harder than thematrix. Consequently, wear rate of the material with higher carbon content is lower that of the lowercarbon content. In addition, the experiment result has shown that the differences of original surfaceroughness of the punches affect the wear rate. Since the better surface quality has a larger asperityangle, the punch having better surface quality will have better resistance to wear. The wear rates forall punches are in the following order: SKD11, SKS3, SKH51 and S50C, as the SKD11 has the lowestwear rate, which is 2.5 times lower than that of S50C.

Keywords : Wear / Blanking Die / Tool Steel / Carbon Contents / Surface Roughness