Recarburizers are indispensable in the process of smelting steel. The use of recarburizers can reduce the amount of pig iron or not use pig iron, save raw materials, thereby reducing production costs, and also reduce resource development and reduce environmental pollution. Today Shengchi Ferroalloy will briefly explain to you the 8 precautions when using Recarburizers in Steel Making.
Item 1: Particle size of recarburizer
If the particle size of the recarburizer is not appropriate, it will affect the absorption rate of the recarburizer. If the particle size is too fine, it is easy to burn, and if it is too coarse, it will float on the surface of the molten steel and will not be easily absorbed by the molten steel.
Matter 2: Recarburizer composition
The composition of the recarburizer should be distinguished by the amount of nitrogen. When using it, it is important to choose a recarburizer with a nitrogen content that meets the requirements! Choose a recarburizer with a nitrogen content that meets the requirements: Generally, you should choose a recarburizer with a low nitrogen content during casting. This will ensure that the harmful substances are smaller. The content of titanium in the molten iron is very low and will not consume a lot of nitrogen. , Because the nitrogen content increases, there will be a lot of pores, gas shrinkage and other defects.
Matter 3: Adding amount of recarburizer
Because under a certain degree of saturation, the more the recarburizer is added, the longer the time required for dissolution and diffusion, the greater the corresponding loss, and the lower the absorption rate. Therefore, if the addition amount is not appropriate, it will also cause the low absorption rate.
Item 4: Graphitization of recarburizer
Pay attention to the use of a good graphitized recarburizer, because the poorly graphitized recarburizer is added to the molten iron, first, the absorption rate is slow and low, second, there are a lot of slag after melting, and third, there are many other harmful elements in it. To the quality of molten iron.
Item 5: Joining time
If the casting recarburizer is added too early, it is particularly easy to make it adhere to the bottom of the furnace, and the recarburizer adhering to the furnace wall is not easy to be melted into the molten iron. On the contrary, if the addition time is too late, then the opportunity to increase carbon will be lost, resulting in slow smelting and heating time. This not only delays the time for chemical composition analysis and adjustment, but may also cause harm due to excessive heating.
Item 6: How to join
The method of addition is also different. If the method of addition is wrong, it will also affect the absorption rate. In the method of adding, do not add the casting recarburizer at once, but add it in several times. Put about a pack of molten iron into the ladle, and then return the recarburizer to the furnace for 1-2 times, then slag and add alloy. Adding too much at one time may cause the recarburizer to be difficult to absorb; too much ash content of the recarburizer and uneven particle distribution; too much nitrogen in the recarburizer, resulting in excessive nitrogen in the finished product.
Item 7: Stirring of molten iron
The recarburizer is easy to burn. If you want to reduce the burn, you need to use stirring. Stirring is beneficial to the dissolution and diffusion of carbon, and it can effectively reduce the burnt loss of the recarburizer floating on the surface. Stirring can also reduce the carbon-increasing heat preservation time, shorten the production cycle, and avoid the burning of the alloy elements of the iron towel. Before the recarburizer is completely dissolved, the stirring time is long and the absorption rate is high. However, if the stirring time is too long, it will not only have a great impact on the service life of the furnace, but after the recarburizer is dissolved, the stirring will aggravate the loss of carbon in the molten iron. Therefore, the appropriate stirring time for molten iron should be when the recarburizer is completely dissolved.
Item 8: Stove selection
In addition, you must also pay attention to choosing a suitable recarburizer for your furnace, because different recarburizers are often applicable to different smelting furnaces. Before purchasing recarburizers, you must fully understand which type of furnace is used. The recarburizer.