| 摘要 |
<p>Cast Fe contg. spheroidal graphte is p graphite is produced by charging the bottom of a ladle with a 1:10-20 mixt. of Mg of particle size 0.05-0.3 pref. 0.1-0.145mm and ferro-Si of particle size 0.05-2.0 pref. 0.1-1.0mm; adding pieces of steel scrap; and filling the ladle with molten Fe. The mixt. added may also contain magnesite of particle size 0.05-1.0mm the mixt. comprising (in wt.%): Mg 5-9, magnesite 10-50 and ferro-Si the balance. The steel scrap pieces are pref. added in an amt. up to 1%, on the amt. of Fe added, to cover the particle mixt. The molten Fe is poured in at 1300-1460 deg.C, the compsn. of the Fe being: 3.0-3.5% C, 1.0-2.0% Si, 0.2-0.5% Mn, 0.03-0.05% P, 0.02-0.1% S and 0.12-0.20% Cr. In a typical process in which 5t. of molten Fe are modified at 1380 deg.C, the process takes 4-5 mins; the fall in temp. is 30-40 deg.C. (not claimed).</p> |
