spheroidizing agent

Spheroidizing agent is certain metals or alloys added into molten iron to obtain spheroidal graphite cast iron. The spheroidizing agent commonly used in my country is rare earth magnesium ferrosilicon alloy. Most foreign countries use magnesium-based spheroidizing agents (pure magnesium and magnesium alloy). A few countries use calcium-based spheroidizing agents. The spheroidal graphite in nodular cast iron is made of molten cast iron after spheroidization, which makes it much stronger than gray cast iron and better toughness than malleable cast iron, while maintaining a series of advantages of gray cast iron. However, the "spheroidizing agent" used in spheroidal graphite cast iron can increase the tendency of the weld to produce "white mouth" and hardened structure, and induce cracks in the weld and the heat affected zone (especially the fusion zone). Therefore, the weldability of ductile iron is worse than that of gray cast iron. 3-8.5-8.7-8 is the grade of spheroidizing agent, which can also be called rare earth magnesium ferrosilicon alloy, Among them, 3, 5, and 7 in 3-8.5-8.7-8 are rare earth content, and 8.8.8 in 3-8.5-8.7-8 represent magnesium content respectively; Spheroidizing agent particle size: 5-30mm (also can be processed according to customer requirements), gray-black solid thickness does not exceed 100mm Characteristics of spheroidizing agent: strong spheroidizing ability, stable composition, stable response, no worry of decline. The composition and particle size can be precisely controlled according to requirements. Spheroidizing agent packaging: 25 kg mother-in-child bag plus ton bag, or packaging according to customer requirements Spheroidizing agent effect: Various grades of rare earth silicon-magnesium alloy spheroidizing agent used for ductile cast iron. After the addition of molten iron, it can be used for spheroidization, desulfurization and degassing, and can improve the purity of the cast water. Melting point impurities play a role in generating lower melting point and do not melt in iron compounds to eliminate these impurities, which can prevent interference elements from destroying spheroidization. The basic requirements of cast iron for spheroidizing agent:

(1) Strong spheroidization ability; 

(2)Abundant resources, low price, and easy to melt; 

(3) Strong adaptability to various components (such as eutectic degree, sulfur content, de-spheroidizing elements and alloying elements) and temperature of molten iron; 

(4) The spheroidization reaction kinetics conditions are good, the reaction is relatively stable, the reaction product is easy to eliminate, the amount is small, the temperature is low, and the spheroidization process is good; < /p>

The adding method of the spheroidizing agent and the quality influencing factors: composition, particle size, shape, density, MGO content, etc. 

(1)The composition of spheroidizing agent is not allowed; 

(2)The spheroidizing agent is powdered, and the alloy particle size does not meet the requirements; 

(3)The density of spheroidizing agent fluctuates greatly, some spheroidizing agents float up quickly, the reaction is too intense, and the safety is not guaranteed;