| 摘要 |
<p>The present invention provides a high-rigidity spheroidal graphite cast iron by lowering the carbon equivalent (CE value) of a spheroidal graphite cast iron and thereby enhancing the Young's modulus thereof. This high-rigidity spheroidal graphite cast iron contains, in mass%, either 2.0 to less than 2.7% or more than 3.0 to less than 3.6% of C, 1.5 to 3.0% of Si, 1.0% or less of Mn, 1.0% or less of Cu and 0.02 to 0.07% of Mg, with the balance being Fe and unavoidable impurities. Further, the high-rigidity spheroidal graphite cast iron has a CE value of 2.8 to 3.2% in the first C content range of 2.0 to less than 2.7% and a CE value of 3.6 to 4.2% in the second C content range of more than 3.0 to less than 3.6%, and exhibits a Young's modulus of 170GPa or more. Each CE value is calculated from the contents of C and Si according to formula (1) CE = C(%) + Si(%)/3.</p> |
