超高張力鋼の疲労変形及び破壊に関する研究

抄録

Deformation and fracture of fatigue in an ultra-high strength maraging stainless steel were investigated to understand the effects of frequency on fracture mechanisms. The servo-hydraulic testing machine was used for fatigue tests at a frequency of 30Hz. After mechanical tests, the fracture surfaces were observed by scanning electron microscope (SEM). It was found that the tensile fracture surfaces show ductile characteristic of dimples although the elongation of the specimen is as low as 3%. The fatigue limit for 10⁷ cycles at 30Hz is 500MPa, which is much higher than that (407MPa) at 20kHz, because of no melting occurred during fatigue tests.