| 摘要 |
PURPOSE:To obtain the titled cast iron having superior mechanical properties and corrosion resistance by austempering high Si spheroidal graphite cast iron having a specified composition contg. C, Si, Mn and Mg to form a bainite structure contg. a large amount of a retained austenite structure. CONSTITUTION:High Si spheroidal graphite cast iron consisting of, by weight, 3.0-4.5% C, 3.0-5.5% Si, 0.2-1.0% Mn, 0.02-0.10% Mg and the balance essentially Fe is austempered to adjust the amount of a retained austenite structure in the matrix to 30-80vol% and the amount of a bainite structure 70- 20vol%. High Si spheroidal graphite bainite cast iron having superior mechanical properties such as hardness, tensile strength, yield strength and elongation and superior corrosion resistance is obtd.
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