摘要 |
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 composition of particles of XaSb or XaOb and 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 XaSb or XaOb particles embedded in a metallic matrix X. The invention further concerns methods for production and use of the composite material. |