The difference between inoculants and ferrosilicon

Some customers of the foundry often do not know the difference between inoculant and ferrosilicon. Some people say inoculant, and others say ferrosilicon. What is the difference?

1. Inoculant introduction:

The inoculant is a kind of inoculant that can promote graphitization, reduce the tendency of white mouth, improve the morphology and distribution of graphite, increase the number of eutectic groups, and refine the matrix structure. good effect. It is mainly suitable for general occurrence or late instantaneous inoculation in various situations.

Inoculation treatment refers to adding a small amount of other substances to the liquid metal during the solidification process to promote nucleation, inhibit growth, and achieve the purpose of refining grains. Traditionally, adding additives to cast iron is called inoculation treatment; adding additives to non-ferrous alloys is called metamorphic treatment. Essentially, inoculation treatment mainly affects nucleation and promotes grain dissociation; while metamorphic treatment changes the crystal growth mechanism (inhibits growth), thereby affecting the crystal morphology.

2. Introduction of ferrosilicon:

Ferrosilicon is an iron alloy composed of iron and silicon. Ferrosilicon is an iron-silicon alloy made of coke, steel scraps, quartz (or silica) as raw materials and smelted in an electric furnace. Since silicon and oxygen are easily synthesized into silicon dioxide, ferrosilicon is often used as a deoxidizer in steelmaking. At the same time, since a large amount of heat is released when SiO2 is generated, it is also beneficial to increase the temperature of molten steel while deoxidizing. At the same time, ferrosilicon can also be used as an alloying element additive, which is widely used in low-alloy structural steel, spring steel, bearing steel, heat-resistant steel and electrical silicon steel. Ferrosilicon is often used as a reducing agent in ferroalloy production and chemical industry.

3. The difference and connection between inoculant and ferrosilicon:

Ferrosilicon is used as an inoculant and nodularizer in the cast iron industry. Cast iron is an important metal material in modern industry. It is cheaper than steel, easy to melt and smelt, and has excellent casting properties and much better shock resistance than steel. In particular, ductile iron, its mechanical properties are at or close to those of steel. Adding a certain amount of ferrosilicon to cast iron can prevent the formation of carbides in iron and promote the precipitation and spheroidization of graphite. Therefore, in the production of ductile iron, ferrosilicon is an important inoculant (helping to precipitate graphite) and spheroidizing agent. 

Common inoculants with good effects include: ferrosilicon inoculants, silicon barium inoculants, and silicon calcium inoculants.