METHOD FOR PRODUCING SPHERICAL GRAPHITE CAST IRON MATERIAL OF FERRITE GROUP HAVING EXCELLENT DUCTILITY AND HARDNESS

摘要

PURPOSE: A production method of spherical graphite cast iron material is provided to be befitting to a material of a heat-resistant component by having the excellent ductility and the hardness. CONSTITUTION: A spherical graphite cast iron material contains C of 2.2-3.8wt%, Si of 3.0-6.0wt%, Mn under 1.0wt%, Ni under 5.0wt%, Cr under 3.0wt%, W under 2.0wt%, Mo under 2.0%, Fe and other impurities and Mg, Zr, Bi and a compound of rear-earth elements of 0.001-1.0wt% added to be spherical of a graphite. The spherical graphite cast iron material is melted in a melting furnace and inoculated to be spherical of the graphite. A surface hardening layer of 2-20mm formed by a fine spherical graphite particle of 10-16micrometers is formed by continuously casting through a copper mold.