The inoculation treatment is to add a certain amount of alloy material to the molten iron before solidification to form a carbon atom activation microdomain around the existing or newly added nucleation matrix in the molten iron. The high activity carbon atoms are detached from the formation of compounds with iron atoms and tend to transfer to the surface of the nucleation matrix...
The inoculation treatment is to add a certain amount of alloy material to the molten iron before solidification to form a carbon atom activation microdomain around the existing or newly added nucleation matrix in the molten iron. The high activity carbon atoms are detached from the formation of compounds with iron atoms and tend to transfer to the surface of the nucleation substrate, which can increase the number of effective graphite crystal nuclei. Promote the smooth growth of graphite. The technical means of promoting the graphitization of molten iron by using a specific foreign substance is called a gestation treatment. The alloying substance used is called an inoculant.
The purpose of gestation:
1. Strongly increase the graphite core, reduce the supercooling of the molten iron, refine the grains, and inhibit the white mouth tendency of the cast iron parts.
2. Improve the sensitivity of the section and partially eliminate the internal stress, so that the elements in the molten iron are evenly dispersed.
3. Control the morphology of graphite, reduce the formation of eutectic graphite and symbiotic ferrite, and obtain medium-sized A-type graphite for gray cast iron.
4. Increase the number of eutectic groups, promote the formation of thin-steel cast tubes, refine and round the graphite balls, and improve the spheroidization level of ductile iron.
5. It can better control the metallographic structure of cast iron, prevent spheroidization and decay, and improve the casting performance and processing performance of cast iron.
The inoculant added for the purpose of promoting graphitization is usually a silicon-iron containing Si72-75% or other complex containing alkaline earth metal elements such as calcium, strontium, barium and zirconium. The Si-based inoculant is called silicon-based gestation. Agent.
The silicon inoculant is a good use effect, and the price of ferrosilicon is relatively low, which is widely used.
There is a significant difference in the role of silicon in the addition of silicon and in the original molten iron in promoting graphitization. The silicon added is mainly controlled by the metallographic structure of the cast iron.
The rapid development of science and technology, the requirements for the performance of cast iron are increasing, and new inoculants have been developed. There are nearly 10,000 kinds of inoculants in the world today. It is also hoped that relevant users will work with us to develop inoculants with higher mechanical properties. .
There are many methods for gestation, such as: one-time gestation, the second gestation, the gestation, the instant gestation, the pre-furnace gestation, the tempering in the ladle, and the production plants operate according to their own experience.
Different methods of inoculation, the chemical composition of the product and the granularity of the inoculant use are different. Therefore, when ordering, the user must agree on the contract.
In particular, it should be noted that: gestation should not be excessive, excessive gestation will produce excessive eutectic groups, reduce the strength of the casting, and will cause the casting to shrink, the crystal grains are coarse, the leakage is serious, and the effect of gestation is not achieved.
At the same time, our company also operates and exports other non-ferrous materials: metal magnesium, metal calcium, rare earth mixed metals, aluminum ingots, etc., which can be supplied according to customer needs.
The above is the introduction of manganese iron manufacturers for the production series, the following are the specific provisions of China's standards:
Description: 1. Physical state: The silicon particles are in the form of silver-gray blocks with a block size of 0.2-1mm, 1-3mm, 3-8mm, 8-15mm. 2. If the buyer has special requirements on the chemical composition and product particle size, the manufacturer can supply the product according to the demand side, and the product is provided with a quality guarantee.