Patent ID: 8133333

Claim:
A method of producing an iron alloy sheet comprising: melting an iron alloy comprising iron, boron, carbon, silicon, chromium, and manganese to obtain an iron alloy melt wherein said iron alloy has a melting point in the range of 1100° C. to 1500° C. and a critical cooling rate for metallic glass formation of less than 10 5 K/s; and cooling said iron alloy melt using a twin belt casting process into a sheet having a thickness of 0.3 mm to 30 mm, by cooling said iron alloy melt between an upper belt and a lower belt, wherein said belts are separated by a distance wherein the distance between the belt surfaces are reduced along the belt length compensating for the shrinkage of said iron alloy and providing constant pressure on said iron alloy as it cools, wherein said sheet is cooled at a rate of less than 10 4 K/s to produce no metallic glass and structural units in the range of 150 nm to 1000 nm, and/or 10 nm to 150 nm wherein said sheet includes α-Fe, γ-Fe and complex borocarbide phases, and wherein said sheet exhibits a hardness HV 300 in the range of 100 kg/mm 2 to 3,000 kg/mm 2 , a tensile strength in the range of 100,000 lb/in 2 to 950,000 lb/in 2 , a tensile elongation at room temperature in the range of 1% to 40% and a tensile elongation at temperatures greater than room temperature in the range of 1% to 280%.