Inoculant is a type of agent that can promote graphitization, reduce the tendency of white spots, improve the morphology and distribution of graphite, increase the number of eutectic clusters, and refine the matrix structure. It has good effects in a short period of time (about 5-8 minutes) after inoculation treatment. Mainly suitable for general natural parts or transient incubation in various situations.
Inoculation treatment refers to the addition of a small amount of other substances to the liquid metal during the solidification process to promote nucleation, inhibit growth, and achieve the goal of refining grains. Traditionally, adding additives to cast iron is called inoculation treatment; Adding additives to non-ferrous alloys is called modification treatment. Essentially, inoculation treatment mainly affects nucleation and promotes grain dissociation; And the modification treatment is to change the crystal growth mechanism (inhibit growth), thereby affecting the crystal morphology.
Ferrosilicon is an iron alloy composed of iron and silicon. Ferrosilicon is an iron silicon alloy made by smelting coke, steel shavings, quartz (or silica) as raw materials in an electric furnace. Due to the easy synthesis of silicon dioxide from silicon and oxygen, ferrosilicon is often used as a deoxidizer in steelmaking. At the same time, due to the release of a large amount of heat during the generation of SiO2, deoxidation is also beneficial for increasing the temperature of molten steel. Meanwhile, ferrosilicon can also serve as an alloying element additive and is widely used in low alloy structural steel, spring steel, bearing steel, heat-resistant steel, and electrical silicon steel. Ferrosilicon is commonly used as a reducing agent in ferroalloy production and chemical industry.
Differences and connections between inoculants and ferrosilicon:
Silicon iron is used as an inoculant and spheroidizer in the cast iron industry. Cast iron is an important metal material in modern industry, which is cheaper than steel, easy to melt and smelt, and has excellent casting performance and much better seismic resistance than steel. Especially nodular cast iron, its mechanical properties reach or approach the mechanical properties of steel. Adding a certain amount of ferrosilicon to cast iron can prevent the formation of carbides and promote the precipitation and spheroidization of graphite. Therefore, ferrosilicon is an important inoculant (helping to precipitate graphite) and spheroidizing agent in the production of ductile iron.