The main cause of overheating of the copper tubes in the mold is local overheating, which leads to the temperature of the copper tubes exceeding their overheating temperature. This is specifically caused by insufficient cooling, improper process parameters, and a combination of material and environmental factors.

I  Cooling system factors

1) Unreasonable water gap design: Poor fluidity of cooling water and insufficient local cooling effect cause the copper tube temperature to rise and lead to overheating and deformation.

2) Insufficient cooling water or scale blockage: Low flow rate or blockage in the water gap reduces the cooling efficiency, causing local overheating of the copper tubes.

2. Process parameter factors

1) Excessive casting speed: The product of casting speed and the viscosity of the protective slag affects heat transfer. An excessively high casting speed increases the heat load and intensifies the risk of overheating.

2) High superheat of molten steel: Excessively high temperature of molten steel increases the heat transferred to the mold, which may cause the temperature of the copper tubes to exceed the overheating point.

3. Material and environmental factors

1) Poor heat transfer performance of copper tubes: Material or coating defects (such as microcracks) affect heat dissipation efficiency, indirectly causing local overheating.

2) Oxidizing atmosphere: Poor performance of the protective slag or strong oxidizing properties of the furnace gas may promote grain boundary oxidation and accelerate the occurrence of overheating.

overheating of the copper tubes in the mold will directly affect the stability of the continuous casting process and the quality of the cast billet. In severe cases, it may lead to production interruption and increased costs.

1. Overheating can cause changes in the surface structure of copper tubes, forming oxide layers or ablated areas, which significantly reduces their heat conduction performance. As the core function of the mold is to rapidly cool the molten steel, a decline in heat conduction capacity will directly affect the uniformity of the shell, increasing the risk of internal cracks, shrinkage cavities and other defects in the cast billet.

2. Overheating of copper tubes can cause cracks, peeling and thermal deformation of the inner surface coating, which intensifies the chemical corrosion and mechanical wear of the base material by molten steel. This not only reduces the number of times the copper tubes can be reused, but also increases the replacement frequency and maintenance costs.

3. The quality of the cast billet and the efficiency of continuous casting are affected. Uneven solidification of the shell can cause accidents such as breakout and bulging, threatening production safety. To avoid risks, the casting speed is often reduced, which restricts the increase of steel output and affects the overall production rhythm.

4. Overheating may lead to the scrapping of the entire copper tube. According to the definition in materials science, overheating refers to the melting of grain boundaries due to excessively high heating temperatures. This kind of damage is irreversible, and the material cannot be restored through subsequent processing; it can only be scrapped. Once a copper tube undergoes substantial overheating, it will directly result in the waste of resources and economic losses.