Intermediate frequency furnace lining is an important part of the intermediate frequency furnace, and it is also a vulnerable part in the intermediate frequency furnace, which often appears cracking, falling off, etc., and needs to be repaired or replaced in time. Before the full pass Xiaobian has introduced the causes of the intermediate frequency furnace lining falling off, then the small series of ** Anaijie manufacturers will introduce what happened to the intermediate frequency furnace lining cracking, the causes of this situation and what are the solutions.

1. Random cracks

Reason: The reason for the random cracks is mostly due to the impact of the cold furnace lining when the block degree is large during the intermediate frequency furnace feeding, and the steel structure of the furnace is not too strong, so that the coil is displaced during the tilting furnace, and the furnace lining is strained and cracked. During the production of a 20-ton intermediate frequency furnace, only half of the molten iron is melted at one time, resulting in the liquid level of the lining being too low, the residence time of the molten iron being too long, and the temperature difference between the top and bottom of the lining being too large, resulting in random cracks when cooling the furnace body.

Solution: During the use of the medium frequency furnace, pay attention to maintaining a high liquid metal surface to be used, so that the furnace wall can evenly accept erosion and erosion, before pouring, to turn on the full power, so that the mixing time is shortened, under normal circumstances, the furnace temperature can be maintained at 1300 degrees Celsius, and as far as possible below 1400 degrees Celsius, so that the melting speed of cold material remains stable; In the melting, frequently scraping slag, can make the metal quickly flow into the molten flow, so as to reduce the corrosion of the slag on the furnace lining. The crucible die is concentrically placed with the induction coil so that its thickness is uniform and its deviation is less than 3 mm.

2. Transverse crack

Cause: There are three reasons for the occurrence of transverse cracks, the more common is that when the knot is tied, the material is not cut loose with a degassing fork, resulting in the delamination between the materials. Secondly, the cooling speed is too fast when the upper lining of the furnace is cooled, and when the temperature difference between the lining and the lower lining is large, the upper and lower shrinkage of the lining in the cooling process is uneven, which is easy to cause strain and transverse cracking of the lining. In addition, due to physical reasons, the structure of the furnace body is loose, which makes the mica backing loose and causes the fault of the furnace lining.

Solution: For the transverse crack, the treatment method mainly starts from the furnace building process, and the weight of the furnace should be consistent with the consumption of the furnace every time, and the density of the furnace lining should be uniform and rammed. After each layer is knotted, before adding the next layer of material, the surface of the solid furnace lining can be loosened about 20mm with a flat shovel, so that the bite between the layers can be tight. Before building the furnace, the charge should be fully mixed to avoid any debris falling during the furnace building process.

3. Longitudinal cracks

Reason: The reason leading to longitudinal cracks is mostly due to the unreasonable rapid cold and hot cycle impact caused by non-standard operation of cold melting, which makes the lining appear longitudinal cracks.

Solution: The knotted lining should be immediately oiled, and the furnace should not be stopped for a week or half a month, and should be continuously melted and insulated to form a thicker sintering layer to resist the tensile stress caused by cooling contraction.

The above is the introduction of the intermediate frequency furnace lining cracking brought by Anaijie Xiaobian. Through reading this article, we can understand the causes and solutions of the intermediate frequency furnace lining cracking, and take preventive measures in advance, which also helps to improve the efficiency of the intermediate frequency work. If you have any other questions, please feel free to call Anetje, we will reply to you in time.