nitrogen conent in the recarburizer

At present, a large number of foundry companies are making synthetic cast iron, using a large number of recarburizers, but there is no standard for using recarburizers in casting. So what is suitable the nitrogen content in the recarburizer?

(1)For coal recarburizers, the nitrogen content depends on the quality of the coal, and the nitrogen content is different, generally between 2000 and 7000 ppm, that is, 0.2% to 0.7%.

(2)Ordinary calcined petroleum coke recarburizer, because it has not been calcined at a high temperature, the calcining temperature may be low and the time may be short. The nitrogen content is generally about 1000 ppm, that is, 0.1%, and the sulfur content is also high, generally about 0.5%, it is generally used into the gray cast iron, it is impossible to draw clear traces on white paper.

(3)High-temperature calcined petroleum coke recarburizer is also called graphitized petroleum coke recarburizer. The nitrogen content is 300～500PPm, which is 0.03～0.05%. The sulfur is much lower than the former, generally 0.05%,generally used in ductile cast iron and gray cast iron.

(4)The best quality high-temperature calcined petroleum coke recarburizer with a nitrogen content of 100PPm. Sulfur is lower than the former. Clear marks can be left on white paper, and it feels comfortable, just like a 6B pencil.

(5)Special reminder is the graphite columnar recarburizer, which is made of graphite powder plus a binder and extruded into cylindrical particles. Because the carbon is in the form of graphite, this recarburizer is particularly well absorbed in the furnace. The nitrogen content can reach 800PPM, which is 0.08%, and the sulfur content is 0.05%. The price is cheaper than ordinary calcined petroleum coke and high-temperature calcined petroleum coke. Low sulphur and low nitrogen, the carbon content is 90%, 92%, 95%, and the absorption rate is relatively high. In comparison, it is a more suitable recarburizer,generally used in ductile cast iron.

If choose the recarburizer with poor quality and high nitrogen content, it is easy to cause defects in the nitrogen hole of the casting. We say that nitrogen can strengthen the cast iron matrix and increase the strength. However, due to the large amount of synthetic cast iron scrap added, the nitrogen content of the molten iron has reached the upper limit. At this time, If the nitrogen content continues to be high, it is easy to cause the nitrogen hole of the casting to be waste, so it is very important to choose proper recarburizer, Anyang Huatuo Metallurgy in various types of recarburizer for more than 20 years, own rich experience of the product, if there any confuse can consult us.