yvonne@nydcasting.com 
1. Basic principle of wire feeding spheroidization process
Wire feeding spheroidization means wrapping a spheroidizer in a steel sheet using a winding device. The steel sheet has specific thickness and width to form a cable-shaped cored wire roll. The wire roll must have suitable strength and a proper filling rate for processing. A wire feeding device then sends the cored wire into a covered processing bag at a set speed. This achieves the spheroidization process by controlled, steady feeding of the spheroidizer. Essentially, steel sheet carries the spheroidizer into the processing bag bottom by wire feeding.
The diameter classification of cored wires on the market is mainly φ9mm and φ13mm. Each cored wire roll is 2500–3000 meters long and weighs about 1–2 tons. The core wire contains 15%–35% magnesium and selectively adds Si, Re, Ca, and Ba. The feeding speed of the cored wire is between 15 and 40 meters per minute. Wire feeding spheroidization includes producing high-magnesium spheroidizer and cored wire coils. It also involves molten iron smelting, wire feeding spheroidization, and molten iron inoculation.
2. Main advantages of wire feeding spheroidizing process
(1) The spheroidizer amount is small, producing little slag and reducing slag inclusions and pores. This improves casting quality and enhances the overall performance.
(2) The spheroidizing advantage of magnesium is fully utilized, and it is easier to obtain small and round graphite balls. Magnesium is the element with the strongest spheroidizing ability, but the boiling point of magnesium is lower than the temperature of molten iron, which is only 1107℃. It is difficult to increase the amount of w (Mg) in the spheroidizing agent by the flushing process. Its value is generally less than 10%, while the amount of w (Mg) in the cored wire is generally between 25% and 35%.
(3) Since the amount of spheroidizing agent added is small, the amount of w (Si) in the molten iron is small, and more recycled materials can be consumed during the batching process, which is extremely beneficial for castings with low production process yield. Generally, for w (S) < 0.020%, the spheroidizing temperature is between 1480 and 1530 °C, the amount of spheroidizing agent added is 1.2%~1.4% when the spheroidizing treatment is carried out by the flushing method, and the amount of cored wire added is 0.6%~0.8% when the cored wire is produced.
(4) The wire feeding spheroidizing station can be enclosed and linked to a dust removal system. This prevents smoke and dust overflow during treatment and greatly improves the workshop environment.
(5) The temperature drop of molten iron treatment is small. The temperature drop of molten iron using the wire feeding method is reduced by an average of 10~20 °C compared with the flushing method, which can reduce the kinetic energy cost, and the metallurgical quality and spheroidizing quality of the molten iron will also be improved.
(6) The wire feeding spheroidizing bag does not need to set up a dam, making the bag maintenance convenient and low in maintenance cost.
(7) The entire operation process can be started automatically with one button, with accurate quantitative measurement and reduced human operation risks.
(8) The weighing and pressing of spheroidizing agent are eliminated, which can reduce labor costs.
(9) The cost of spheroidizing one ton of molten iron of ordinary ductile iron is lower than that of the flushing method.