フェライト基地球状黒鉛鋳鉄の低温における静的及び動的3点曲げ特性 [in Japanese] Static and Dynamic Three-Point Bending Characteristics of Ferritic Spheroidal Graphite Cast Iron at Low Temperature [in Japanese]
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Static and dynamic bending tests of ferritic spheroidal graphite cast iron were carried out at temperatures range from room temperature to 77K. Bending load-time curves obtained by using instrumented Charpy impact testing machine are converted to load-deflection curves. The relationship between bending load <i>P</i> and deflection <i>δ</i> is well expressed by <i>P</i>=<i>Dδ<sup>n</sup></i> in both of static and dynamic tests, where <i>D</i> and <i>n</i>' are constants. <i>D</i> and <i>n</i>' obtained are both larger than the expected respectively. Constant <i>D</i> in dynamic test is larger than that in static at the same temperature by 17%, regardless of the testing temperature. This difference coincides pretty well with the measured strain rate exponent of flow stress 0.0103. The critical deflection just before fracture <i>δ</i><sub>c</sub>, is proportional to fracture strain of specimen at loading point. Fracture energy <i>W</i>, the area surrounded by the load-deflection curve and abscissa graphically, can be numerated by <i>W</i> = <i>P</i>m<i>δ</i><sub>c</sub> / (1 + <i>n</i>'), where <i>P</i><sub>m</sub> denotes the maximum bending load. The strain rate dependence of transition temperature for the iron seems roughly similar to that of steel.
- THE JOURNAL OF THE JAPAN FOUNDRYMEN'S SOCIETY
THE JOURNAL OF THE JAPAN FOUNDRYMEN'S SOCIETY 70(8), 563-568, 1998-08
Japan Foundry Engineering Society