The development of nodulizer plays an important role in promoting the production of nodular iron. The scarce source of cerium, as a nodulizer that had long been recognized, and the strict requirement on the composition of molten iron make cerium nodular iron unable to be used in industrial production. Magnesium nodulizers enable nodular iron to be applied on an industrial scale. The development of nodulizers from pure magnesium to magnesium-nickel, magnesium-copper, and magnesium-silicon-iron has promoted the expansion of nodular iron production. With rare earth magnesium-silicon-iron nodulizers, our production of nodular iron no longer relies on foreign resources. The series of rare earth magnesium nodular iron in China, which expands the use range of pig iron, improves the performance and quality of nodular iron castings, and makes nodular iron production flourished even more. The application of Y (heavy rare earth) has created conditions for the development of new compound nodulizers. The comprehensive utilization of various nodular elements will create favorable conditions for the further development and improvement of nodular iron production.
The basic requirements for nodulizers are:
(1) It shall have strong spheroidization ability;
(2) It shall be low-price and easy to melt, with abundant resources;
(3) It shall have strong adaptability to molten iron with various components (such as eutectic degree, sulfur content, anti-spheroidization elements and alloying elements) and temperature;
(4) It shall have good and stable dynamic conditions of the spheroidization reaction, with products easy to remove, small usage and temperature drop, and good spheroidization treatment process.