| 摘要 |
PURPOSE:To form a chill layer without using any chiller by teeming molten metal prepd. by contg. specific amts. of Pb and N2 in ordinary gray cat iron composition into a mold. CONSTITUTION:In a method for forming a chill layer of gray cast iron, the molten metal contg. 150-500ppm Pb and 150-300ppm N2 in ordinary gray cast iron composition is prepd., and such molten metal is teemed in a mold. The gray cast iron composition used is ordinary composition ranging 2.9-3.5% C, 1.7- 2.3% Si, 0.4-0.8% Mn, 0.01-0.15% P and 0.01-0.15% S. |
