PRODUCTION OF EUETCTIC GRAPHITE CAST IRON AND SPHEROIDAL GRAPHITE AST IRON BY VACUUM LADLE DEGASSING PROCESS OF MOLTEN CAST IRON

摘要

PURPOSE: To obtain eutectic graphite cast iron and spheroidal graphite cast iron improved in fluidity and to produce extra thin cast iron products by pouring molten metal into a low pressure tank and treating the molten metal under a low pressure. ;CONSTITUTION: The eutectic graphite cast iron is produced by adding extremely small amounts of inorganic matter to molten cast iron in a low-pressure tank and performing alloying. Further, the spheroidal graphite cast iron is produced by adding extremely small amounts of rare earth and subrare earth elements. These eutectic graphite cast iron and spheroidal graphite cast iron are reduced in gas content and surface tension and improved in fluidity, and the production of extra thin cast rion of ≤2mm thickness hitherto considered to be impossible is made possible. Moreover, the tough and free-cutting eutectic graphite cast iron can be produced, and ≥100mm wall thickness sensitivity can be attained.;COPYRIGHT: (C)1995,JPO