号数	ばね論文集 58 号（ 2013 年）
ページ数	pp.41-48
種類	共同研究
論文名	ばねの遅れ破壊に関する研究委員会報告その１ ―CSRTとねじり試験による遅れ破壊評価法の検討―
Title	Evaluation of Delayed Fracture Properties for Spring Steels Part I -Application of CSRT and Torsional test-
著者	ばねの遅れ破壊に関する研究委員会
Author	The Research committee on Evaluation of Delayed Fracture Properties in Spring Steels
抄録
Abstract	Influences of tensile strength, hydrogen concentration and applying stress mode (tension or torsion) on delayed fracture properties have been investigated using SAE9254 steel treated in their tensile strength range of 1700-2000MPa. In conventional strain rate techniques (CSRT), the delayed fracture strength tends to decrease with the increment of diffusible hydrogen concentration, especially less than 1 mass ppm. On the other hand, in torsional tests, the hydrogen cracking susceptibility shows less abrupt change than in CSRT, while the fracture torque decreases and intergranular cracks are observed in the notch root of specimen when hydrogen is charged above 10 mass ppm.
著者の所属
Belonging
Key Words	Delayed fracture, Hydrogen cracking, Diffusible hydrogen, Conventional strain rate technique, Torsion, Spring steel, SAE9254