ALLOY WITH FREE AND FIXED CARBON AND METHOD OF ITS PRODUCTION Russian patent published in 1999 - IPC

FIELD: metallurgy. SUBSTANCE: alloy has component forming crystal structure of solid solution based on iron and particularly soluble in iron and structurally free phase-forming nonmetallic component in the form of particles whose size is not less than the size of critical seed charge and thermodynamically distributed uniformly in volume of component forming crystalline structure with ratio of nonmetallic component in free and soluble and fixed state from 0.01 to 20. Article made of the alloy is distinguished by the fact that it has structurally free phase-forming nonmetallic component in the form of black with particles sizing 10^-5-10^-7 cm with the following ratio of components, mas.%: carbon in soluble and fixed state, 0.01-1.00; free carbon, 0.01-2.24; iron, the balance. Method of production includes melting of low-carbon semiproduct. Iron charge is used in the form of iron of direct reduction and/or pig iron which is charged into melting unit in liquid, and/or solid form in amount of 75-100%. Melt is overheated by 20-70 C higher than liquidus temperature. Carburization is effected with carbon in the form of black with particles sizing 10^-5-10^-7 cm which is introduced in the amount of 0.01-2.14% of melt weight in discharge, and/or in refining, and/or in casting. Alloy is deoxidized by elements whose affinity to oxygen is equal or higher than that of aluminum to oxygen in the amount of 0.05-3% of melt weight to provide for ratio of free and fixed carbon in alloy equalling 0.01-20.0. After refining and casting, crystallization and treatment of alloy are carried out by pressure. EFFECT: higher ductility with preserved material strength. 9 cl, 2 tbl