PURPOSE: To prepare a thin cast iron piece reduced in surface defect and structural irregularity and having good quality, by a method wherein a Sc value, a Si amount, a S amount and a Mn amount in chemical components are specified and molten iron having a seed charge such as an Fe-Si alloy inoculated therein within a laddle is subjected to horizontal continuous casting.
CONSTITUTION: In the chemical components of molten iron to be subjected to continuous casting, a Sc value is adjusted to 0.99W1.08%, Si to 3.1W3.3%, S to 0.020W0.060% and Mn to S%×1.7÷0.3% while a seed charge such as a Fe-Si alloy or a Ca-Si alloy based on Si is innoculated in the above mentioned molten iron within a laddle to prepare a cast iron piece having a cross area shape wherein the ratio of a long side to a short side (a flatness ratio) is 4 or more and the length of the short side is 25mm or less according to a horizontal continuous casting method. By this method, a cast iron plate completely free from a cementite crystal in the corner part and the end surface part thereof, having a chill depth of about 3mm or less at the corner part thereof in a 45° direction, reduced in defect and having good quality can be obtained.
KODAMA JIYUNICHI
OKA ISAO
ITOU ISAO
SUZUKI KIYOSHI
| JPS521881A | 1977-01-08 |