Precautions for petroleum coke recarburizer in cast iron

1. The component of the recarburizer is a non-metallic material with a melting point of about 1200°C to 1300°C. Its main components are fixed carbon, sulfur, ash, volatile matter and water. At present, people mainly distinguish the types of carburetor by the proportion of nitrogen and sulfur content. The more scrap steel is added to the electric furnace, the greater the proportion of nitrogen in the molten iron. Due to the low harmful elements such as titanium, lead, and antimony in molten cast iron, low-nitrogen recarburizers should be used. If the recarburizer has a high nitrogen content, it is easy to cause nitrogen pores in the casting. Generally speaking, low-end recarburizers have relatively high nitrogen content. If a carburizer with a high nitrogen content is used, nitrogen pores will occur. If the sulfur content in the recarburizer is high, it will also affect the quality of the casting. Therefore, it is very important to choose a suitable recarburizer in cast iron. Carbon fiber spun pitch

2. Graphitized recarburizers with good product quality differences can stabilize recarburization and promote absorption. If the recarburizer with poor graphitization is added to molten iron, the absorption rate is low, the absorption rate is slow, and the furnace produces more slag. It is easy to cause the nitrogen content of the molten iron to exceed the standard, resulting in nitrogen holes. Sometimes the pore defects are not large, and the reason is estimated to be related to molten iron, such as titanium, pickaxe and other elements, which have good nitrogen affinity. This is also the reason why a large number of customers in the market use low-sulfur and low-nitrogen recarburizers.

3. How to add recarburizer When making cast iron, the amount of recarburizer is very large. It can be added in the early or mid-stage of electric furnace smelting and feeding, and it is added at the same time as scrap and silicon carbide. It involves the pretreatment of the post-melting volume to increase the role of graphite, and then a carbonizing agent with a low nitrogen content must be added. It is recommended not to exceed it, not exceeding 0.2%, to avoid coarse graphite. Then, the better temperature of the molten iron is about 1500 degrees, and it is added to the cleaning liquid surface of the cleaning slag. After a few minutes, the temperature is suitable for the furnace, regardless of whether the remaining carbonizer is not absorbed on the liquid surface, because it can still Play a role in the impact and stirring process of molten iron.

Because the content of titanium in the molten iron is very low, it is unlikely that Ti will consume a lot of nitrogen, so that castings are very prone to nitrogen pores, crack-like nitrogen pores or related defects due to too high nitrogen content. The huge loss caused by the poor quality of the recarburizer is very much the production of pig iron smelting. The key is to use the calcined petroleum coke with good quality and low nitrogen content. Many foundry friends believe that the high sulfur content of the recarburizer is not easy to harm the quality of general gray iron (creating pig iron), but the high sulfur content of the recarburizer will also be high with the nitrogen in it, which will cause product quality problems. . The quality of the recarburizer is the key to pig iron smelting. The amount of recarburizer added can also directly cause harm to the smelting. Once the nitrogen hole appears, it will be assessed as a defective product. It is sold at a low price, or it can’t be used directly, and the waste is discarded. The proportion of defective products is too large, which means that this batch of pig iron does not make money, and even loses money.

The way of adding recarburizer is very large when producing pig iron. It can be added in the early or middle period of electric furnace smelting and feeding, and it can be added in addition to scrap steel, and silicon carbide can be added in conjunction with each other. Among them, the amount of addition involved in the middle and late stages of smelting has the preparatory treatment to enhance the leading role of high-purity graphite. At this time, a recarburizer with low nitrogen content must be added. The addition amount does not need to be too much, not exceeding 0.2%, to prevent the high-purity graphite from becoming thick. To fill the recarburizer, the ideal molten iron temperature is around 1500 degrees. Add the clean liquid surface of the slag. After more than ten minutes, the temperature can be released. You don’t need to pay attention to the residual recarburizer that is not digested and absorbed by the liquid surface, because it is in During the impact stirring process of the molten iron from the furnace, it can also have a creative effect. Precautions for petroleum coke recarburizer in cast iron

1. The component of the recarburizer is a non-metallic material with a melting point of about 1200°C to 1300°C. Its main components are fixed carbon, sulfur, ash, volatile matter and water. At present, people mainly distinguish the types of carburetor by the proportion of nitrogen and sulfur content. The more scrap steel is added to the electric furnace, the greater the proportion of nitrogen in the molten iron. Due to the low harmful elements such as titanium, lead, and antimony in molten cast iron, low-nitrogen recarburizers should be used. If the recarburizer has a high nitrogen content, it is easy to cause nitrogen pores in the casting. Generally speaking, low-end recarburizers have relatively high nitrogen content. If a carburizer with a high nitrogen content is used, nitrogen pores will occur. If the sulfur content in the recarburizer is high, it will also affect the quality of the casting. Therefore, it is very important to choose a suitable recarburizer in cast iron.

2. Graphitized recarburizers with good product quality differences can stabilize recarburization and promote absorption. If the recarburizer with poor graphitization is added to molten iron, the absorption rate is low, the absorption rate is slow, and the furnace produces more slag. It is easy to cause the nitrogen content of the molten iron to exceed the standard, resulting in nitrogen holes. Sometimes the pore defects are not large, and the reason is estimated to be related to molten iron, such as titanium, pickaxe and other elements, which have good nitrogen affinity. This is also the reason why a large number of customers in the market use low-sulfur and low-nitrogen recarburizers.

3. How to add recarburizer When making cast iron, the amount of recarburizer is very large. It can be added in the early or mid-stage of electric furnace smelting and feeding, and it is added at the same time as scrap and silicon carbide. It involves the pretreatment of the post-melting volume to increase the role of graphite, and then a carbonizing agent with a low nitrogen content must be added. It is recommended not to exceed it, not exceeding 0.2%, to avoid coarse graphite. Then, the better temperature of the molten iron is about 1500 degrees, and it is added to the cleaning liquid surface of the cleaning slag. After a few minutes, the temperature is suitable for the furnace, regardless of whether the remaining carbonizer is not absorbed on the liquid surface, because it can still Play a role in the impact and stirring process of molten iron. Recarburizer manufacturers

Because the content of titanium in the molten iron is very low, it is unlikely that Ti will consume a lot of nitrogen, so that castings are very prone to nitrogen pores, crack-like nitrogen pores or related defects due to too high nitrogen content. The huge loss caused by the poor quality of the recarburizer is very much the production of pig iron smelting. The key is to use the calcined petroleum coke with good quality and low nitrogen content. Many foundry friends believe that the high sulfur content of the recarburizer is not easy to harm the quality of general gray iron (creating pig iron), but the high sulfur content of the recarburizer will also be high with the nitrogen in it, which will cause product quality problems. . The quality of the recarburizer is the key to pig iron smelting. The amount of recarburizer added can also directly cause harm to the smelting. Once the nitrogen hole appears, it will be assessed as a defective product. It is sold at a low price, or it can’t be used directly, and the waste is discarded. The proportion of defective products is too large, which means that this batch of pig iron does not make money, and even loses money.

The way of adding recarburizer is very large when producing pig iron. It can be added in the early or middle period of electric furnace smelting and feeding, and it can be added in addition to scrap steel, and silicon carbide can be added in conjunction with each other. Among them, the amount of addition involved in the middle and late stages of smelting has the preparatory treatment to enhance the leading role of high-purity graphite. At this time, a recarburizer with low nitrogen content must be added. The addition amount does not need to be too much, not exceeding 0.2%, to prevent the high-purity graphite from becoming thick. To fill the recarburizer, the ideal molten iron temperature is around 1500 degrees. Add the clean liquid surface of the slag. After more than ten minutes, the temperature can be released. You don’t need to pay attention to the residual recarburizer that is not digested and absorbed by the liquid surface, because it is in During the impact stirring process of the molten iron from the furnace, it can also have a creative effect.