Tianjin Global Alloy Material Co., Ltd.

Steelmaking NodulizerThe additive that makes the graphite in cast iron crystallize into spheres is called "spheroidizer". The main components of "spheroidizer" are spheroidizing elements, such as Mg, Ce, Ca, etc. The spheroidal graphite in ductile iron is formed by spheroidizing the cast iron liquid, which makes its strength much higher than that of gray cast iron and its toughness better than that of malleable cast iron, while maintaining a series of advantages of gray cast iron. However, the "spheroidizer" used in the melting and casting of ductile iron can increase the tendency of "white cast iron" and hardened structure in the weld, and induce cracks in the weld and heat-affected zone (especially the fusion zone). Therefore, the weldability of ductile iron is worse than that of gray cast iron.

The spheroidizer commonly used in my country is ferrosilicon rare earth magnesium alloy, while most foreign countries use magnesium spheroidizers (pure magnesium and magnesium alloys), and a few countries use calcium spheroidizers.

The development of Steelmaking Nodulizer plays an important role in promoting ductile iron production. Cerium was a spheroidizer that was confirmed very early. At that time, the source of cerium was scarce and the requirements for the composition of molten iron were strict, so cerium ductile iron could not be used in industrial production. Magnesium spheroidizers enabled ductile iron to be produced and applied on an industrial scale. The development of spheroidizers from pure magnesium to magnesium-nickel, magnesium-copper, and magnesium-silicon-iron alloys promoted the expansion of ductile iron production. The development of rare earth magnesium-silicon-iron spheroidizers has basically based my country's ductile iron production on domestic resources, established my country's rare earth magnesium ductile iron series, expanded the scope of pig iron use, improved the performance and quality of ductile iron castings, and made ductile iron production more prosperous. The application of yttrium heavy rare earth has created conditions for the development of new composite spheroidizers. The comprehensive utilization of various spheroidizing elements will create good conditions for the further development and improvement of ductile iron production.

The basic requirements for Steelmaking Nodulizer are:

(1) Strong spheroidizing ability;

(2) Abundant resources, low price, and easy to melt;

(3) Strong adaptability to molten iron of various compositions (such as eutectic degree, sulfur content, anti-spheroidizing elements and alloying elements) and temperatures;

(4) Good spheroidizing reaction kinetics, relatively stable reaction, easy removal of reaction products, small amount of use, less cooling, and good spheroidizing processability.