Taboo 1: Prohibition of the use of moist inoculants
When the moist inoculant is added to the molten metal, the moisture in the molten metal reacts with the metal element in the molten metal at a high temperature to form a metal oxide and hydrogen, and the generated primary hydrogen dissolved in the molten metal causes defects such as subcutaneous pores in the casting. Therefore, the inoculant should not be wet.
Taboo 2: It is forbidden to use pure silicon or pure ferrosilicon as an inoculant
Pure silicon or ferrosilicon containing no calcium, barium, strontium or aluminum is not used as an inoculant because the graphite is heterogeneous nucleus precipitated by iron in the molten iron, and sulfur is oxidized by silicon germanium. The heterogeneous nucleus can prevent the iron from being too cold and white. Silicon ferrite containing at least 1%-2% calcium, 0.05-0.5% aluminum, and 75% silicon is used as an inoculant, or silicon-zirconium, silicon-calcium, silicon-lanthanide, silicon- High-efficiency inoculant such as lanthanide.
Taboo 3: Inoculants should not be added rashly, pay attention to methods
If the inoculant floats on the surface of the metal, it will oxidize quickly and is difficult to be absorbed by the molten metal. Therefore, when the flushing method is used, it should be accurately added to the contact of the molten iron with the liquid surface or with the chute. Because the inoculation method has a direct impact on the inoculation effect, it can also be used in the pouring cup, the ferrosilicon rod breeding, the large floating silicon inoculation, the inoculation, the inoculation, and the intra-inoculation.
Taboo 4: The particle size of the inoculant should not be too thick or too fine
If the particle size is too coarse, it cannot be melted and absorbed by the molten iron more quickly, and the mixing of the remaining unmelted inoculant particles into the casting will deteriorate the performance or cause scrapping. The particle size should not be too fine, and the powdery inoculant is easily oxidized and burned, loses the inoculation effect, and causes the castings to be slag.