Anyang Metallurgical Refractories Company tells you how to choose nodulizer and inoculant?

1. Selection of spheroidizing agent:
(1) Magnesium content of 4%, 5%, 5.5% belongs to low magnesium spheroidizing agent, RE is between 1% and 2%, and is mostly used for smelting in intermediate frequency furnace and spheroidizing of low-sulfur molten iron. It has the advantages of gentle spheroidization reaction and easy absorption of spheroidizing elements.
(2) The magnesium content of 6% and 7% belong to the medium magnesium series spheroidizing agent, which is mostly used for double smelting of cupola and electric furnace, or smelting of pearlite cast ductile iron castings in intermediate frequency furnace. According to the casting wall thickness and the sulfur content of the original molten iron, determine the appropriate amount of spheroidizing agent, which has a wide range of applications and a wide range of spheroidizing treatment processes.
(3) High-magnesium series spheroidizing agent, suitable for cupola smelting, molten iron with sulfur content of 0.06%-0.09%, and the addition amount is between 1.6%-2.0%.
(4) Low-aluminum spheroidizing agent is used for castings that are prone to subcutaneous pore defects and castings that require aluminum content in molten iron.
(5) The spheroidizing agent produced by pure Ce and pure La, after spheroidizing, the molten iron has less pure inclusions and the graphite balls are round. The spheroidizing agent produced by yttrium-based heavy rare earth is suitable for large-section castings, delaying the spheroidization recession and preventing massive graphite. Sb-containing spheroidizing agent is used for pearlite nodular cast iron.
(6) Low-silicon spheroidizing agent is suitable for foundries that use a large amount of recycled materials; nickel-magnesium spheroidizing agent is used for high-nickel austenitic ductile iron.

2. The choice of inoculant:
(1) Si, Ba, Ca, Al alloys are widely used, with ideal inoculation effect and low dosage. Barium is an extremely active element, low calcium barium silicon barium inoculant, strong graphitization ability, is the recommended choice for gray cast iron, ductile iron, vermicular graphite cast iron castings.
(2) Deoxygenation inoculant, which has strong deoxidation effect, increases silicon, saves cost, and is used to prevent pores and subcutaneous pores.
(3) The strontium silicon inoculant does not increase the number of eutectic clusters in gray cast iron, but it has good graphitization effect and has a significant effect on preventing thin-wall and uneven thickness castings from whitening. Therefore, it can prevent thin-wall and uneven thickness castings (cylinder body). , Cylinder head) leakage.
(4) High-aluminum and low-calcium ferrosilicon inoculant has a significant effect on eliminating gray iron and white mouth. The bismuth-containing ferrosilicon inoculant makes up for the lack of obvious effect of single addition of bismuth. Silicon-zirconium inoculant can refine austenite dendrites and improve the strength of cast iron. The addition of manganese to the inoculant can lower the melting point of the multi-element alloy to facilitate diffusion and absorption in the molten iron. The effect of the inoculant of silicon, calcium, barium, and manganese is particularly outstanding in this respect.
(5) Rare earth inoculants have special effects on reducing the brittleness of white cast iron. For high-grade hypoeutectic gray cast iron, it can significantly improve the graphite morphology, without deliberately reducing the carbon content, it can also increase the strength of the cast iron, thereby improving the machining performance.
(6) The inoculation block in the mold is a treatment method that saves resources and has a good inoculation effect. The pouring system is equipped with a foam ceramic filter, and the two constitute a combination for producing high-quality castings. The inoculation block will be favored by more foundry companies.
(7) The specially produced covering agent has pure ingredients and uniform particle size, which is more conducive to obtaining stable and high-quality casting products.