| 摘要 |
This invention is directed to a method of hot reducing ferrous and ferrous alloy products, such as plates, strip, bars and rods, where such products are heated to temperatures in excess of 1900 DEG F and subsequently reduced at temperatures within the range of about 900 DEG and the initial heating temperature. More particularly, this invention relates to the method of effecting said hot reducing at such temperatures by means of composite, martensitic, nodular graphite chill cast iron rolls. Such rolls are characterized by (1) an average surface hardness of at least about 76 Shore-C, (2) a thermal-crack-resistant chill cast surface portion consisting essentially of, by weight, about 3.00% to 3.70% carbon, about 0.35% to 1.25% manganese, about 1.0% to 2.0% silicon, about 3.75% to 5.75% nickel, about 0.75% to 1.35% chromium, about 0.40 to 1.10% molybdenum, about 0.3% to 0.08% magnesium, balance iron and incidential impurities, and (3) a core portion comprising a ferrous alloy. |
