PROCESS FOR MAKING AS-CAST FERRITIC SPHEROIDAL GRAPHITIC DUCTILE IRON

摘要

2086943 9201072 PCTABS00010 A process for making ferritic spheroidal graphite iron uses no pig iron but instead melts medium manganese and low silicon content steel scrap in an electric furnace with about 3 % by weight of low sulphur content graphite. When the melt reaches 1400 ·C it is deslagged. Sufficient graphite is then added to bring the carbon up to at least 3 % again and before or after this event, returns may be added to the melt while the furnace electric power is on to induce stirring of the melt. The melt is superheated next to above 1470 ·C and carbon and silicon correction is made. This is followed by inoculating the melt and pouring the castings.