| A study on making the high strength Cast Iron by the small amount of copper addition in the ordinary component range was conducted, while tensile strength, hardness and microstructure by the variation of the amount of copper addition were investigated. The results obtained from this study are as follows; 1) When a small amount of copper was added to cast iron, the reifegrad became higher when the degree of S.C. was 0.88, the addition of copper increased the average reifegrad by 110. 2) The variance of tensile strength by addition of copper is as follows. In the case of 2.8% carbon, 1.9% silicon, the tensile strength was increased by addition of 0.75% copper and in the case of 3.1% carbon, 2.4% silicon, it was increased by addition of 1.5% copper. But, it was decreased beyond those copper values. In the case of 3.1% carbon, 2.4% silicon and 1.5% copper, the tensile strength was increased by 25% compared with that without copper addition 3) The variance of hardness by addition of copper is as follows. In the case of 2.8% carbon, 1.9% silicon, tensile strength was increased by addition of 0.75% copper and in the case of 3.1% carbon, 2.4% silicon, it was increased by addition of 1.0% copper. But, it was decreased beyond those copper values. In the case of 3.1 % carbon, 2.4% silicon and 1.0% copper, the hardness was increased by 14% compared with that without copper addition. |
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