Host: The Japan Society for Precision Engineering
Rotational tools are usually subjected to combined loading of bending and torsion under cutting work. In this investigation, SKH51 (AISI M2) high speed steel was solution heat treated in the range of 1160°C to 1260°C and then tempered until 650°C.An appropriate heat treatment condition was found in terms of strength characteristics, fracture mechanisms and static fracture toughness obtained from loading tests in tension, bending and torsion. With increasing solution heat treatment temperature, the strength rose to maximum value at 1200°C and then decreased when the specimen were tempered at 560°C. Additionally, the bending strength was higher than the shearing and the tensile strengths. Brittle fracture occurred without plastic deformation in both tension and bending tests, whereas plastic deformation was produced in torsion test.
