Ferro Silicon Inoculant

 

Ferro silicon inoculant is an additive which is mainly used in metal casting process. Adding ferro silicon inoculant can adjust the metal composition and improve the quality of castings. Ferrosilicon inoculant is an essential additive for casting process. It can eliminate defects such as shrinkage holes and sand holes in castings, improve the mechanical properties and surface finish of castings, and increase the density of castings.

 

 

Ingredients	Content	Function
Si	65%~75%	Core component for graphitising
Fe	approximate 25%~35%	Matrix element, forms stable alloy with silicon
Ca	0.5%~1.5%	Enhances breeding effect
Al	0.5%~1.5%	Improves breeding activity, but too high increases inclusions
C	≤0.1%	Low carbon content to avoid interference with graphitising
P	≤0.04%	Excessive phosphorus reduces toughness of cast iron
S	≤0.02%	Sulphur easily forms sulphide inclusions, affecting performance

 

 

一. Preparation

(1) Selection of suitable inoculants

Before joining the casting requirements to choose a suitable inoculant, ferrosilicon inoculant mainly has four types: ordinary ferrosilicon inoculant, calcium silicon inoculant, strontium silicon inoculant, barium silicon inoculant. Different types of inoculants have different effects, for example: ordinary ferrosilicon inoculants are used for general grey cast iron and ductile iron. Calcium silicon inoculant is usually suitable for high demand castings, to enhance the effect of inoculation.

After choosing a good inoculant, we should check its particle size to ensure its dissolution speed and diffusion effect.

(2) Calculate the amount to be added

The amount of ferrosilicon inoculant is generally 0.2% to 0.8% of the weight of iron, and the specific dosage should be adjusted according to the type of casting, iron composition, casting size and other factors.

(3) Pretreatment

Ferrosilicon inoculant is easy to absorb moisture, and should be stored in a dry environment before use.

Before adding iron, the inoculant can be preheated to 200~300℃ to reduce the impact on the iron temperature.

 

二. Add inoculant

Ferrosilicon inoculants are mainly added to the package inoculation, with the flow of inoculation, inoculation, according to the casting process and equipment conditions to choose the right way. The operation of in-bag gestation is simple and suitable for small batch production. With the flow of breeding breeding effect is uniform, suitable for automated production. In-type gestation has a high utilisation rate of gestation agent and is suitable for complex castings.

 

三. Control parameters

(1) Iron temperature

Optimum temperature range: 1400~1500℃. Too low a temperature will lead to insufficient dissolution of inoculant, too high a temperature may cause inoculation decline.

(2) Inoculation time

The inoculant should be poured as soon as possible after it is added to avoid affecting the inoculation effect.

(3) Stirring and mixing

After adding the inoculant, it can be mechanically or manually stirred to promote its uniform distribution.

 

四. Precautions

(1) Strictly control the holding time of molten iron

(2) Strictly control the content of impurities

(3) The product should be stored correctly

(4) Match the casting requirements