Sinvent As

Elkem Asa

Oystein Grong

Gabriella Maria Tranell

Ole Svein Klevan

Casper Van Der Eijk

Leiv Olav Kolbeinsen

The present invention concerns a new type of grain refiners for steel, in the form of a particulate composite material, containing a high volume fraction of tailor-made dispersed particles, with the purpose of acting as potent heterogeneous nucleation sites for iron crystals during solidification and subsequent thermo-mechanical treatment of the steel. The material comprises a position of particles of XSor XOand the element(s) X, where X is one or more elements selected from the group Ce, La, Pr, Nd, Y, Ti, Al, Zr, Ca, Ba, Sr, Mg, Si, Mn, Cr, V, B, Nb, Mo and Fe, and S is sulphur, (O is oxygen), wherein said material additionally contains oxygen, sulphur, carbon and nitrogen, wherein the sulphur (or oxygen) content is between 2 and 30% by weight of said material, while the total content of oxygen (or sulphur), carbon and nitrogen and said other elements selected from the group X is between 98 and 70% by weight of said material, and the said material contains a high volume fraction of finely dispersed XSor XOparticles embedded in a metallic matrix X. The invention further concerns methods for production and use of the composite material.

Grain refiners for steel-manufacturing methods and use

The present invention relates to a method for grain refining of steel. 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, said alloy containing at least 10inclusion particles per mmconsisting of oxides and/or sulphides and/or carbides and/or nitrides 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 &#x3bc;m, is added to molten steel in an amount of between 0.01 and 5% by weight based on the weight of the steel, whereafter the steel is cast. The invention further relates to a grain refining alloy for steel and to a method for producing grain refining alloys.

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Tiller, Norway

Oystein Grong