ADDITIVES REDUCING STEEL GRAIN SIZE, MANUFACTURING METHODS AND USE Russian patent published in 2012 - IPC C21C7/00 C22C35/00 B22D27/20 

FIELD: metallurgy.

SUBSTANCE: invention refers to metallurgy and can be used during modification of steel melting with additives in the form of composite material containing high volume ratio of specially manufactured particles. Material includes composition of particles (X_aS_b) or (X_aO_b) and element X, where X - one or several elements chosen from group of Ce, La, Pr, Nd, Y, Ti, Al, Zr, Ca, Ba, Sr, Mg, Si, Mn, Cr, V, B, Nb, Mo and Fe, and S - sulphur, O - oxygen, where the above material also includes oxygen, sulphur, carbon and nitrogen; at that, "a" and "b" - arbitrary positive numbers which are determined with total content of elements S, O, C, N and X, where content of sulphur or oxygen is between 2 and 30% of the weight of the above material, while total content of oxygen or sulphur, carbon and nitrogen and the other specified elements chosen from group X is between 98 and 70% of the weight of the above material, and the above material includes high volume ratio of particles (X_aS_b) or (X_aO_b) built in metal matrix X.

EFFECT: invention allows developing composite material which is added to molten steel prior to casting operation as strong centres of heterogeneous nucleation for iron crystals during hardening and further thermal mechanical steel treatment.

31 cl, 6 dwg