オーステンパ球状黒鉛鋳鉄の室温と中高温における疲労特性
1995 年 44 巻 501 号 p. 776-781
詳細
1995 年 44 巻 501 号 p. 776-781
Rotating bending fatigue tests of smooth specimens were carried out using an austempered ductile cast iron (ADI) in the temperature range between room temperature and 400°C. In order to clarify the fracture origin, the fracture surfaces were investigated by SEM. The amount of retained austenite was measured by X-ray diffraction method.
The fatigue limit reached maximum at about 300°C due to not only the transformation of retained austenite but also the cyclic strain ageing. The retained austenite transformed at 350-400°C. Due to the surface hardening by the transformation and strain ageing, most of the cracks caused at elevated temperatures initiated at the location of internal defects.
