During the production of casting iron and graphite iron, there is a crucial step called inoculation. Inoculation helps to improve the mechanical property of the iron.
To complete the inoculation process, several additives must be added. These additives are called the inoculant.
The purpose of inoculant
The function of inoculant is to improve the nucleation ability of the graphite and to stabilize the solidification of the iron. Although the amount of inoculant added is very small, they have a large impact on the inner structure of the iron. To be specific, the inoculant is used to:
- avoid or reduce the chilling phenomenon;
- avoid excessive cooling;
- increase the nucleation;
- distribute the graphite structure in an even way.
The main forms of inoculant
In the practice, the available types of inoculant on the market are in either granular form, or stuffed in a wire, or pressed in different shapes.
On product-wise, the main types of inoculants are ferro silicon, silicon calcium, and silicon calcium added with another element, such as silicon barium calcium.
Silicon calcium
Silicon calcium is a common type of inoculant, it also can be used in other applications, such as deoxidizer and desulfurizer, or warming agent.
When it is used as inoculant in the process of production of cast iron, in addition to deoxidation and purification, the silicon calcium alloy also plays a role in inoculation, helping to form fine-grained or spherical graphite. It can increase silicon, desulfurize, and improve the quality of cast iron.
Please check this page for more specifications on silicon calcium.
Ferro silicon
The ferrosilicon inoculant is formed by crushing the ferrosilicon into small pieces and filtering through a certain mesh of a sieve. It is a cheap substitute for expensive inoculants and nodularizer.
Please visit here for more information on ferro silicon product.
Silicon barium calcium
Silicon barium calcium is a new type of deoxidizer in steelmaking, and it has good desulfurization and phosphorus ability. It plays a very important role in the smelting of steel with low sulfur and phosphorus. It has a wide range of applications in special steel systems. prospect.
Specification of silicon barium calcium
| Si | Ba | Ca | C | P | S | |
| ≥ | ≤ | |||||
| Si50Ba15Ca10 | 50.0 | 15.0 | 10.0 | 0.40 | 0.05 | 0.05 |
| Si50Ba13Ca13 | 50.0 | 13.0 | 13.0 | 0.40 | 0.05 | 0.05 |
| Si50Ba16Ca8 | 50.0 | 16.0 | 8.0 | 0.40 | 0.05 | 0.05 |
| Si45Ba10Ca8 | 45.0 | 10.0 | 8.0 | 0.40 | 0.05 | 0.05 |
| Si45Ba15Ca10 | 45.0 | 15.0 | 10.0 | 0.40 | 0.05 | 0.05 |
Silicon barium
The silicon barium inoculant is mainly used for the inoculation of ductile iron and grey cast iron liquid. The silicon barium inoculant strongly increases the graphitization core, refines the graphite, promotes the A-type graphite in the grey iron castings, and improves the strength. For the ductile iron castings, it can make the graphite in the ductile iron fine, round and improve the spheroidization grade.
Strong resistance to decline while preventing the associated spheroidization decline. The wall thickness is less sensitive and the organization is uniform. Significantly reduce the tendency of white mouth, reduce the relative hardness, and improve the cutting performance of castings. It is used as an inoculant and spheroidizing agent in the cast iron industry.
Specification of silicon barium
| model | size（mm) | Si | Ba | Ca | Re | Fe |
| Si50Ba30 | 1-10 | 50 | 30 | — | ||
| Si72Ba4-6 | 1-10 | 72 | 4-6 | — | ||
| Si72 | 3-8 | 70-72 | — | — | — |
Size:
0-0.25mm: used for intra-mould inoculation (precise inoculation, higher efficiency)
0.2-1mm: used for inoculation with the flow (the control of the inoculation volume is more accurate)
1-3mm and 3-8mm are used for inoculation in the bag (the incubation time must be controlled at more than 70% of the iron extraction time)
8-15mm for incubation in the furnace
Standard particle size of silicon barium inoculant: 0.1-0.4mm, 0.2-0.7mm, 1-3mm, 3-6mm