1. Selection of spheroidizing agent:

(1) The content of mg 4%, 5% and 5.5% belongs to low Mg spheroidizing agent, and re is between 1% and 2%. It is mostly used for medium frequency furnace melting and spheroidizing treatment of low sulfur molten iron. It has the advantages of mild spheroidization and easy absorption of spheroidized elements.

(2) The content of magnesium is 6% and 7%, which belongs to medium magnesium series spheroidizing agent. It is mainly used for cupola, electric furnace double melting, or medium frequency furnace melting of pearlite ductile iron castings. According to the thickness of the casting and the sulfur content of the original hot metal, the appropriate amount of spheroidizing agent is determined, which has a wide range of application and a wide range of spheroidizing process.

(3) It is suitable for cupola melting with 0.06% - 0.09% sulfur content of molten iron, and the addition amount is between 1.6% - 2.0%.

(4) Low aluminum nodularizing agent is used in castings which are easy to produce subcutaneous porosity defects and castings which require aluminum content in molten iron.

(5) The spheroidizing agent produced by pure CE and pure La has the advantages of less inclusions and round graphite balls. The spheroidizing agent produced by yttrium based heavy rare earth is suitable for large section castings to delay spheroidizing decline and prevent massive graphite. Sb containing nodularizing agent is used for pearlite ductile iron.

(6) The low silicon nodularizing agent is suitable for foundry with large amount of recycled materials; Ni mg nodularizing agent is used for high Ni Austenitic Ductile iron.

2. Selection of inoculant:

(1) Si, Ba, CA, Al alloys are widely used, the inoculation effect is very ideal and the amount is small. Barium is a very active element, low calcium barium silicon barium inoculant, graphitization ability, is gray iron, ductile iron, vermicular iron casting choice.

(2) Deoxidizing inoculant has strong deoxidizing effect, increases silicon, saves cost, and is used to prevent pores and subcutaneous pores.

(3) Silicon strontium inoculant does not increase the number of eutectic clusters in gray cast iron, but the graphitization effect is good, and the effect of preventing the thin-walled and uneven thickness castings from white spot is remarkable, so it can prevent the leakage of thin-walled and uneven thickness castings (cylinder block and cylinder head).

(4) High aluminum and low calcium ferrosilicon inoculant has remarkable effect in eliminating gray iron. Bismuth containing ferrosilicon inoculant can make up for the defect that the effect of adding bismuth alone is not obvious. Si Zr inoculant can refine austenite dendrite and improve the strength of cast iron. The effect of Si Ca Ba Mn inoculant is especially prominent in this respect.

(5) Rare earth inoculant has special effect on reducing brittleness of white cast iron. For high grade hypoeutectic gray cast iron, the graphite morphology can be obviously improved, and the strength of cast iron can be improved without deliberately reducing the carbon content, so as to improve the machinability.

(6) the inner inoculation block is a way to save resources and breed good results. The ceramic foam filter is added to the gating system, and the two constitute a combination of high quality castings. Inoculation block will be favored by more foundry enterprises.