inoculation for cast iron

In casting production, the use of inoculants to improve the quality of castings is now a common technical means, especially with the cupola exiting the foundry industry, the application of electric furnaces, and the large amount of scrap used in foundry production.

However, the foundry knows little about the principles of inoculation technology and the role and composition of inoculants. A little carelessness can cause irreparable damage. Next, I will spread some expertise in inoculants for everyone. Everyone's reference;

Precautions for the addition of inoculants:

(1) Ductile iron is generally added more than the inoculant of gray cast iron;

(2) If the molten iron is inoculated after treatment, the amount of addition should be increased due to the decline of fertility;

(3) Thin-walled castings are prone to white mouth, and the amount of inoculant added should be increased accordingly;

(4) When there is a large amount of slag in the molten iron, since the inoculant is in contact with the slag, it will be wrapped and difficult to melt, so the amount of addition is correspondingly increased;

(5) If the inoculant is added in excess, it will cause problems such as a decrease in the temperature of the molten iron and a shrinkage of the granules. If the inoculant is too large, it will not be able to evenly fertilize the molten iron, and the unmelted inoculant will be poured into the cavity; if the block is too small, it will easily oxidize and cause slag, and it is prone to gestation and decline;

(6) The inoculant used in the inoculation method is small, generally 0.2~0.8mm, and the added amount is 0.05%~0.2%; the block size of the inoculation method is generally ≤0.25mm, and the added amount is ≤ 0.1%;The weight of the remaining inoculation method is generally 1~10mm, and the addition amount is 0.1%~0.8%.

Introduction to silicon barium inoculant:

The silicon barium inoculant (long-acting inoculant) in huatuo  metallurgical manufacturers

Content: Si: 68% - 72%, Ba: 2% - 5%, Ca: 1.5%

Silicon barium inoculant use:

For: ductile iron

0-0.25mm: for intra-inoculation (precise and efficient, higher efficiency)

0.2-1mm: used in the inoculation agent (the control of the amount of gestation is relatively accurate)

1-3mm, 3-8mm for intra-bag breeding (pregnancy time must be controlled above 70% of the time of tapping)

8-15mm for furnace gestation