摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a method of reutilizing steel sheet scrap for efficiently obtaining cast iron of high quality while preventing needless increase in cost using steel sheet scrap containing high tensile strength steel sheet scrap. <P>SOLUTION: In a batch recovery stage, high tensile strength steel sheet scrap and common steel sheet scrap are collectively recovered, and, after that, in a preparation stage, the recovered steel sheet scrap is dissolved, and, preparation is performed in such a manner that, when manganese is contained in≥0.7 wt.% in the molten metal, the content of sulfur is controlled in 0.02 to 0.2 wt.%, and rare earth elements or misch metals are added in an amount double the content of sulfur. When spheroidal graphite cast iron is obtained, after that, a spheroidization agent (preferably, the one which does not contain rare earth elements, and contains bismuth) is further added thereto. <P>COPYRIGHT: (C)2003,JPO</p> |