Crucible Steel
Crucible or cast steel was first invented by Huntsman, of Sheffield, England, in 1740. He succeeded in effecting the complete fusion of blister-steel in crucibles--using the common crucible-furnace and heating with coke surrounding the pot. This was finally poured into cast-iron ingots for the production of homogeneous steel. Whilst the above represents the manufacture of homogeneous steel by melting blister-steel alone in crucibles, there are other methods extensively practised for the production of steel in crucibles by fusing carbon, black oxide of manganese, or spiegeleisen in small proportions along with bar iron or puddled steel. A crucible mixture for tool cast steel is as follows:
Swedish bar iron ..... 50 pounds. Cast-steel scraps ..... 30 pounds. Ferro-manganese ..... 1/2 pounds. Charcoal ..... 1/2 pounds. Salt ..... 1/2 pounds.
See BLISTER-STEEL; PUDDLE-STEEL; STEEL.