タップ用高速度工具鋼の破壊強度に及ぼす負荷形式の影響

概要

論文の詳細を見る
In this study, tension, bending, torsion, and compression tests were carried out to examine the effect of loading mode on fracture strength of SKH51 (AISI M2) high speed tool steel. In addition, the fracture mechanism of each loading mode was examined using scanning electron microscope. Specimens were tempered up to 650°C after solution treatment in the range from 1160°C to 1260°C. It was shown that bending strength was higher than tensile strength up to 1240°C. This phenomenon was explained by introducing the concept of effective volume. Brittle fractures occurred in both tension and bending. Quasi-cleavage fracture patterns were observed on fracture surfaces, and primary carbides were found at the origin of fracture. On the other hand, plastic deformation occurred in torsion and compression, and dimple patterns were observed on fracture surfaces. It was proved that the deformation characteristic of high speed tool steel was dependent on hydrostatic stress component.
公益社団法人精密工学会の論文