How to choose the nodulizer when in the process of spheroidization

Nodularizers and inoculants are the most important materials in the nodularization process of ductile iron. When choosing the right nodularizing agent, in addition to stable quality, the following factors should be considered.

Spheroidization process: If masking is not used, the smoke produced by the spheroidization reaction will enter the atmosphere, producing a dazzling white light. To stabilize the spheroidization reaction, nodularizing agents with low magnesium and high calcium can be used. If the ladle process is used, the molten iron will not splash and will produce less soot, so a nodularizing agent with high magnesium and low calcium can be used to reduce the dosage and spheroidization cost.

Silicon content: If the process yield of the casting product is low or the scrap rate is high, it needs to be melted by adding more charge and scrap steel, and the final casting has strict requirements for the silicon content of the molten iron. Under the premise that the inoculation amount cannot be further reduced, low silica nodularizing agent can be used for treatment, which can increase the recycled material by 8%~15% and reduce the casting production cost.

Sulfur content of raw molten iron: If the sulfur content of raw molten iron is high, no desulfurization treatment is carried out, and a nodularizing agent with high magnesium and high rare earth is required, and the addition amount will be higher; If the sulfur content of the raw molten iron is low, a low-magnesium low-rare earth nodularizer can be used, and the dosage is also lower, and the cost of low-magnesium low-rare earth nodularizer is also lower.