Patent ID: 7226493

Claim:
Method for grain refining of steel, comprising: providing a grain refining alloy having a composition FeXY where X is one or more elements selected from the group consisting of Cr, Mn, Si, Ni and Mo and where Y is one or more oxide and/or sulphide and/or nitride and/or carbide forming elements selected from the group consisting of Ce, La, Nd, Pr, Ti, Al, Zr, Ca, Ba, Sr, Mg, C and N where X is between 0.001 and 99% by weight based on the weight of the alloy and where Y is between 0.001 and 50% by weight of the alloy, said alloy additionally containing between 0.001 and 2% by weight of oxygen and/or between 0.001 and 2% by weight of sulphur; quenching said alloy in a molten state such that said alloy contains at least 10 3 inclusion particles per mm 3 consisting of oxides and/or sulphides and/or nitrides and/or carbides of one or more of the Y elements and/or one or more of the X elements Cr, Mn and Si in addition to Fe, said inclusion particles having a mean diameter of less than 10 μm, adding said quenched alloy to molten steel in an amount of between 0.01 and 5% by weight based on the weight of the steel; and casting said steel.