which of the following ferrous metals has the largest amount of carbon? a. steel b. wrought iron c. cast iron 2. which of the following ferrous metals is least corrosion resistant? a. steel b. wrought iron c. cast iron 3. an integrated mill produces steel using a. steel scrap. b. iron ore. c. 25% to 50% iron ore plus 25% to 50% scrap. d. none of the above. 4. the mini-mill method of steel manufacturing predates