灰铸铁的切口强度与切口敏感性

The Notch Strength and Notch Sensitivity of Gray Cast Iron

总结了国产灰铸铁的抗拉强度与抗拉切口强度、抗弯强度与抗弯切口强度的试验研究结果。结果表明,不论在拉伸或弯曲载荷下,灰铸铁的切口强度约等于其抗拉强度或抗弯强度,与试件应力集中系数Kt无关。这表明灰铸铁的切口强度比,即切口强度对断裂强度之比(NSR)等于1.0,亦即灰铸铁对切口不敏感。结合灰铸铁的显微组织,简要分析了对切口不敏感的原因。

Test results of the fracture strength and the notch strength of gray cast iron under tension and bending loading are summarized in the present paper. Test results show that the notch strength of gray cast iron is approximately equal to its fracture strength and independent of the stress concentration factor of test specimens, i.e., the ratio of notch strength to fracture strength (NSR) of gray cast iron is equal to 1.0. This indicates that the gray cast iron is insensitive to notch in both tension and bending loading conditions. The reason is briefly discussed in combining with the microstructure of gray cast iron.